Exhaust opinions/options.

First of all this is my set up:

K20A Long Block Darton Sleeved
87mm Wiseco pistons 11.7:1
Eagle Rods
Stock K20 "ITR" head
PRC IM
Injen Intake
Hondata IM gasket
OBX Race Header "waiting to install"
Kpro "on the way"
Stock 02-04 exhaust

I've been reading a lot about which exhaust diameter is the best for my set up and my "goals" with the car. A lot of my friends are running K24's/k20 with RBC's, big Throttles, Stage 2+ cams and top of the line headers with 3" full exhausts without resonators and they are all making 270+whp with their set ups. But their cars are so damn loud that i can hear them coming miles away and i dont want to deal with that because 1st my car is DD and 2nd i "assume" that my set up will not get the full benefit of a full 3" cat back.

So, obviously all of my friends advice me to get a full 3" catback. But like I said before, I think that is a little over kill for my set up and my goal with the car is "220-230 whp" with good power in the mid range area with my current set up.

My question is which "piping diameter/exhaust combination" will get me to that numbers without being so damn loud.

Thanks

Exhaust opinions/options.