If you are going the path of a bomber there are only 2 good armors to choose from and 1 decent one. And with bombs you also have a choice of either getting Nitronome, DBB or a status bomb. RSS isn't too useful as DBB beats it in most ways while the rest of the bombs are a joke.

Armor
The two sets to choose from to be an all out bomber, or a bomber with a side are the Mad Bomber or The Mercurial Demo suit. The Volcanic Demo set is more suited for those are half bombers. If you really look at it either one way or the another. If you want to start the game as a bomber you will have probably have to get the Mad Bomber set because there is no way for you at the moment to get anywhere close to beating the shadow lair. So in the eyes of a bomber, Mad Bomber suit is the only real choice. And those who keep it safe and get Volcanic suit before Mad Bomber regret it and buy one later. So in reality due to the difficulty of getting the Mercurial Demo suit you really have ONE choice. Bombastic is not even up on the table for looking at due to how horrible it is.

Bombs
I still sometimes wonder if going into bomb was a good idea. There are tons of swords useful for tons of situations and some used for all. While there damage is amazing high without trinkets and UV's and such. While even with Insane UV and all the trinkets you could dream of a Bomb will never be able to compete with a gun or sword. Once again your choices are limited. You MUST get a Nitronome. And its generally a good a idea to pick up a DBB for wolvers and fiends. In the status bomb category you get 1 great bomb and 2 decent bombs. Great one being shivermist and decent ones which are AoA and Voltic. The other status bombs don't compete at all. I would not recommend RSS at all. RSS is hard to use. Fiends are too small and too fast to hit with a shard. You only real chance is to pray they step on it which is rare or set up shiver and place one behind another which usually results in another fiend throw something at you. So its only decent for undead if you can line them up and gun puppy sniping which it might lose if they change RSS stats like they said they would which also result in it being useless. Evidently DBB>RSS. All other bombs are a joke. The gravity series from personal experience blow. They can screw over you party big time and you should stay away from it as their damage also sucks. The rest such as Big angry, Irontech, ISB etc etc are once again like Bombastic, not even worth considering as they are a joke.

Suggestion
Instead of adding new and amazing swords,content or anything just fix bombing. Been bombing for months now and it sucks, every bomber can see that. At the start we have a choice of one and a half armor or two if you rich enough to spend 1 million in the auction house to buy a Merc Demo Suit because its impossible to get there without paying big time. Choice of 2 bombs and 3 decent optional bombs.
What would make every bomber satisfied would be to either fix bombastic or add all together another DECENT armor. Raise the damages of bombs or change to damage cap to it can even been seen to compete with guns and swords. Add a bomber similar to Nitronome that does shadow damage and continue the firework and coldsnap line as it would change bombing significantly.

Information about me and why I am saying this
I have been a bomber for many months now. I have found that in comparison to everything else bombing lacks a lot of things. I have found myself time and time again telling myself that somehow its worth it and realistically its not. I have tried every bomb besides the Big angry bomb, Irontech D and ISB and I don't need to as time and time again you have heard many others explain how horrible they are and in general everyone knows how bad those bombs are. On the wiki itself it even explains it self how useless those bombs bombastic armor is, its really not that hard to see. Besides months of experience being a bomber myself I also must say it costs A LOT to be a bomber.I still find myself not being up to par with all the money, bombs, trinkets etc I have spent. While if you look around to be a swordsman all you need to buy is Levi and Wolver and your done.

On a final note I would like to say one last thing to anyone who reads this. As long as bombing remains in its current state STAY AWAY FROM IT. Right now its only for those who would like to try something new rather than swords or guns. And at the moment after months of bombing, months of saving up crowns and CE to upgrade and buy everything I could to be the best I can, at this time I truly regret it. So please fix and whats needed before bombing becomes a lost art.

RSS=Radiant sun shard
DBB=Dark Briar Barrage
AoA=Ash of Agni
ISB=Ionized Salt Bomb

@Wolfkit

I know and understand the purpose of the gravity series bombs. The problem I find with gravity bomb are:1) while charging you move incredibly slow leaving you open. 2) While they are in the vortex I often see those with swords before they can unleash their charge are often hit prior to its release, What I mean is whilst in the vortex they can still attack you in any direction. 3) Since Wolfkit himself said it isn't meant to do damage it would be a WAY better idea to invest in a Shivermist as its way better and covers more situations ans problems. 4) Its area sucks.