I'm new to the Integra world; I just picked one up three days ago, but I do have a recomendation.
What seems to work well at least for me is, if I were you, for the cat-back exhaust at least, I'd find the catalytic converter, resonator (if you want one), and muffler online on websites like
www.summitracing.com or
www.andysautosport.com., then go to an exhaust shop and get one custom built. For example, and this is not precise pricing by-no-means, but just what I remember from my research:
Random Technology catalytic converter - $99.00, Dezod Motorsports
Cherry Bomb glasspack (for resonator) - $30.00, 8" length, 3" diameter case, Summit Racing
Hooker Maximum Flow muffler - $69.00, Summit Racing
Exhaust piping - $100.00 (rough guess)
That way, you have a custom system that not everyone else owns, it's guaranteed to fit, it won't cost you too much (this configuration would be a hair over $300 if my in-head math is correct), and you'd be able to fine tune your sound. Check YouTube for sound clips, but remember; it'll always sound a little different than what they show, but it does give you a general idea.
As far as cold air intakes/short ram intakes, whatever, I'd personally just replace the OE filter with a K&N and call it a day. With a short ram, you'd risk extra heatsoak, and with a cold air intake, depending on the filter location, you'd risk hydrolock.
Hope this helps.
