Bigger injectors will do **** all for your almost stocko V6 dude. You would need a bigger fuel pump, even if you got that, pouring more fuel into your engine isn't going to help with power, it will just waste fuel. Bigger TB will do **** all as with the mods you have, you can put a bigger TB on, but your engine won't suck more air in because of it (unless of course you had it tuned).
Try a set of good extractors for your exhaust, a flash tune from either Greenfoam, Doctor Bob or Delcowizzard (all forum members), a stage 2 shift kit and a good CAI.
Gutting your cat is a dumb idea too, if a cop notices that (which a trained one could due to the awful noise it emits), so go to the wreckers and buy a stock cat and put that in. It does sweet F/A for power and even if it did, it's not worth the fine you would get for having a gutted cat.