Gear for Tier 3

Basically I reached Tier 3 yesterday, starting off with an Ash Tail Set + Mighty Defender and Avenger + Faust + Silversix
The 2 big swords knocking everything back and siliversix for kiting around anything I wanted to get away from tactic worked fine for tier 2 content (then again you could get away with pretty much anything). However in tier 3 I'm finding the swords leave me open for too long espically considering the amount of mobs that have a tendency to very quickly get around, namely behind, you. Not to mention that the slow swings usually leave me chasing a mob thats already been knocked back when I'm in a group. With the unforgiving damage in tier 3 this has left me using my silversix more than anything only really pulling out the swords on occasion, especially in arenas.
I'm looking to upgrade my Ash Tail to Vog Cub which seems to be the safest bet and am considering switching from the Defender to an Owlite (only really took defender because I can't stand how owlite shields pre grey look)
My main problem is I'm unsure about what weapons to take as my current set-up definitely needs changing, but I have very little experience with the other weapon lines (never even used a Calibur!) I have the CE/crowns/tokens available to buy/alch my way straight to the 4* versions But am seriously unsure about what weapons to take. I'm mainly a sword user with a gun as backup and have very little experience with bombs, will have all 4 weapon slots, Any advice would be much appreciated.
I'm currently considering an Ascended Calibur as my base weapon with possibly the Faust/Avenger? and a Cyro Driver for utility with my last weapon being the Silversix or possibly a Freezing Automizer
I roll avenger/faust as well, and the best advice i can give you for t3 is to not use the second swing unless youre very confident that it wont leave you open. Swing/shield, swing/sheild leaves you very protected. Between the knockback and the high damage per swing, even on the first swing, i really like the sealed swords. Once you get divine avenger you can use its charge liberally when in situations where you dont want anything near you, just evade while charging then wait for them to get close and let it rip into a large group, if you hit several with the close range swing and then blast a bunch back it will give you back your breathing room while dealing a massive amount of damage. Works great on everything except gremlins and err whatever else resists ele.
Also i do recommend going owlite instead if you can bear it, much more protective in more situations in my experience.
Oh yeah, and the cold iron vanquisher sucks, not worth doing significantly less damage to everything else for a small boost to undead. A low UV vs undead would be way more efficient.

Consider the Cold Iron Vanquisher instead of the Leviathan path. They're both great in their special little way, but damage against undead will help a lot.. and undead mobs in Tier 3 are really dangerous (people quit parties all the time because of graveyard, and there is always Vanaduke).
Looks like someone's not been paying attention to the hundreds of posts about how awful CIV is. Worse in every single way.
Seconding the suggestion of using an Owlite series shield, as the Shock resist will definitely come in handy.
Neh, Laviathan > CIV. I have a CIV and never use the bonus since zombies are way easier to gun/bomb, yet suffer the lower damage against everything else.
Owlite is a great all-purpose shield, plus going Vog will make your slow swords a little faster.
I'd recommend getting Flourish > Final Flourish line for dealing with Wolvers, Greavers and Devilites. These are all a pain to fight in T3, regardless, and Flourish has a very fast interrupt rate that pretty much leaves your target helpless until its dead. Only equip it when you know you're going to need it more than something else, however! (e.g. upcoming strata has a lot of Beasts and Fiends)
Ignore Cold Iron series, lol. If you want a faster sword that Undead are weak to, go with a fire or ice Brandish, but given you have Avenger and Silversix there's really no point in getting yet another weapon for undead.
Ascended Calibur would be a nice alternate to your Sealed swords due to faster attack speed, although as DragnHntr said, Swing > Shield is a great way to play it safe and take a lot less damage in T3, especially when you're in a group. (More chaos, harder to kill a single target before it harms you, etc.)
For me, I'm finding that I like playing to mob weaknesses. When solo, I stopped equipping my Leviathan and use the Brandish series (shadow & ice) and Flourish instead. This requires a lot of weapon switching, but lets me mow down a single target quickly. It's fun, aggressive play, but obviously more risky than swing > shield. Leviathan has more reach and is probably smarter for group play, however.
I'm having a lot of success even with the Brandishes and Flourish only at 4* -- I've cleared to the Core several times with only swords equipped too, so bombs/guns aren't a requirement, just a play style/preference.
Beyond that, check the gatemap before entering... do you have a weak spot for what you're about to encounter? (e.g. shock strata blow goats) Try picking a gate with critters in it you know you're effective against. Doing this will make your trips into T3 more fun, BEFORE you get any more gear!

Firstly thanks for all the responses,
I think I will be getting an owlite for the obvious ele def boost,
The Flourish sounds like a good idea for dealing with what I'm currently having problems with so I'll definitely give testing one a go along with the calibur, main reason I'm leaning towards an Ascended Calibur > Levi is as it seems to be the best all round sword as a base weapon, though probably wouldn't really be needed if I'm carrying both a slow and fast sword.
Fairly sure I want to hang onto my avenger to get it to a divine avenger as the charge looks amazing for survival but at the same time I do love the curse aspect of the faust so I guess where I'm stuck is would be is it worth carrying 3 swords and loosing the use of a freeze bomb (with maybe using Cyro Driver instead of silversix) or just switching whether I'm carrying the Avenger or Faust, though a freeze bomb also looks like it could solve the problems v wolvers etc.
Basically out of a Calibur, Sealed Swords, Flourish, Silversix, Freeze gun/Freeze Bomb what would be the best combination(s) to use, I'll probably end up with all of them at 4* to test but any advice on what to go for first would be appreciated.
(on a side note yay actually managed to reach the core a few times today, not much of an achievement but still lol)
Yeah go with a Leviathan instead of a CIV. You should be carrying a Divine Avenger as well, and that will cover your needs against the Undead.
I roll with Leviathan, Divine Avenger, Gran Faust, and Argent Peacemaker. The Gran Faust is basically there for Gremlins.
I prefer the idea of a damage trinity plus a utility slot, myself. Final Flourish, GF, Combuster and a Shivermist Buster is my combo.
Consider the Cold Iron Vanquisher instead of the Leviathan path. They're both great in their special little way, but damage against undead will help a lot.. and undead mobs in Tier 3 are really dangerous (people quit parties all the time because of graveyard, and there is always Vanaduke).
The Shivermist buster (or any freeze bomb) is an amazing bomb to have in Tier 3. It buys you time, lets you get strategy going, etc. It makes shock arenas fairly easy and makes taking down large groups of gremlins possible (especially with the healers).
Gun wise, the Argent Peacemaker/Silversix is just fine. I wouldn't double up a freeze bomb and a freeze gun, so something kind of generic is helpful.
Lastly, consider getting both the faust and avenger and swapping them out depending on the strata. I have both but use the faust line waaay more simply because curse is addictive. Obviously if you are fighting undead the avenger rocks. You could say the same with construct, but honestly you can just curse them too. It's really only the undead that you'll really want the avenger for.