Ok, here is my idea... Input appreciated!

[Astroman]

Ok, so I've decided my next performance mods will be to help the car breath easier. I've already done the CAI and DC Sports header, and as of right now the rest of the IHE system is stock.

My plan is to use the 1ZZ throttle body (spacer if it's a good idea, might go nitrous), remove one of the catalytic converters and go full custom exhaust after that. The shop that will be doing the exhaust bent and installed the 3" setup and intercooler piping on my Lebaron and they did a great job for around $400 so I will be going back there again. Where I live there are no inspections, but I do want to keep one of the cats, or replace it with a high flow variety (which I did on the Lebaron).

What should I be looking for? I've read the '05 Corolla TB will work but I wanna know exactly what I will need to do to make this work, along with what type of muffler I should be using. I'm wanting it to sound nice but not ricy at WOT, have a nice idle sound, but at cruising be relatively quiet. I'm also thinking a dual-tip center exit as I won't ever be reinstalling a hitch again.

So, lets see what you all have to say about this, bonus points for those who've actually done these things. Also, anyone have any idea how much extra power this might free up?