Build help

At the moment I have
Blizzbrand
Silent Nightblade
Heavy Plate Mail
Miracle Hood
Scary Skelly Shield
and eventually, with full weapon and trinket slots, I know for sure that I want
Glacius
Acheron
Divine Veil
Dread Skelly Shield
Graviton Vortex
The basic idea being to plant the vortex, charge up the Glacius, (hopefully) freeze some or all of the enemies sucked in and then charge up an attack that is best against their type (Another Glacius-charge against elemental weak, an Acheron-charge against shadow weak, and perhaps getting a Flourish to have a piercing charged attack too).
I'm torn between either the Ancient Plate Mail or the Volcanic Plate Mail.
With the Ancient I could get two of the fire and shock resist trinkets and just equip as needed to have full resist depending on what strata I'm on. I'm rather curious to see how good the defense is on this armor given that it reduces movespeed and attackspeed.
With the Volcanic I could get two of the shock resist trinkets and always have full fire and shock resist. Also I'd have wicked elemental resistance from this.
Any thoughts or opinions on what I should do? Note that I'm not looking into UVs yet. I'm merely acquiring a quick, good set of equipment with which I can easily run T2 and perhaps even T3 if I have a good enough party.
I love the graviton... but I don't equip any bombs myself. I like the way it gathers monsters together for my charged levi and/or alchemer richochets. Excellent team bomb, but I don't know how it works solo.
I have to agree with Sick and Senshi, Graviton is a bit on the annoying side to use. The charge time is slow and you walk at about 1/2 speed when charging. Also the radius is small and the suction time is short, so your party members might be able to do a charge attack but you probably won't have the time to do so if soloing.
I usually use a Wise Owlite Shield, but right now I'm leveling my Sinister Skelly Shield to turn into a Dread Skelly Shield. The problem I'm running into repeatedly in T3 and even the last depths of T2 is that it breaks after just a few hits from a Gun Puppy since their attacks are elemental and the skelly series lacks elemental defense. Becomes very frustrating when up against 3+ gun puppies in bullet hell; doubly so if they are freeze or shock. You'll want to invest in a shield that has elemental defense like Grey Owlite Shield or something that has very high normal damage like Omega Shield which can take quite the beating before cracking.
Volcanic Plate Mail will be more useful than Ancient Plate Mail for the Firestorm Citadel. Then with 50 Almirian Seals from Vanaduke you can trade in for Ancient Plate Mail. :)
I suggest trying the 4* GraviTron first to see if it suits your style. Many people despise the use of them due to its slow charge time, slowed walk speed, and the annoying blow-back it causes. Charge time can be alleviated with demo gear but I doubt you will want to wear gear specifically for just one bomb and CTR UV's for Graviton are very hard to come by. The Vortex's suction works for about 3 seconds (a bit longer than the 4*) which is another reason to try it out to see if you can time a Brandish charge before the blast.