You are obviously set on a draw thru. Just get the biggest offerings and live with what you end up with. Looks seem more important than function here anyway. If you like the look of a draw thru system, then you need to be prepared for all the down sides that go with it. The less than stellar all out performance goes hand in hand with very poor cold start, laggy spool up, poor cyl to cyl distribution, detonation, explosive boost tubes, etc...
I've gone this route, and believe me, it aint worth the hassle if power is what you're after. For cruise nights or whatever it looks kinda cool, but than you have to come up with a long list of excuses to tell the guys that want to race you.