Glad to hear the good news! That's great! I hope a clutch is all it needs.
Power's easy with bolt-ons, a lot easier with VE and turbos. But, if you're sticking to NA, this is good to read
http://www.sr20-forum.com/all-motor/40-newbs-basic-na-tuning-guide.html
If you're trying to stay under a budget, stay away from turbo, and pretend you've never heard of VE. If cash isn't a problem, a T25 is good for about 350-400 whp, a T28 is good for even more. If cash really isn't a problem, then VE if you're doing NA (about 170hp bone stock), VET if you want some crazy power numbers. However, there's some DET or DE+T monsters out there in the high 400s in hp and close to that in tq, it all depends on your tune. BenFenner knows a lot about that (definitely a hell of a lot more than me, I'm still pretty green), good guy to pester with this type of question.
How much power are you talking? Just a bit more pep? Or tire-smoking tranny-breaking pep? NA the best you can do with stock internals is somewhere around 175-180 whp, that's where most people hit a wall and start spending buttloads of cash that would have been better spent on going turbo or going VE for about half the power they could have. I personally would be ecstatic about making 170 whp NA. If I get there, I'll hang on to that till I got another DD and a real job, then I plan to slap on a T25 and go for about 275whp and somewhere close to that in TQ. I'd wet myself if I broke 300. The DE block is a tough sommamabitch (RIP Bernie Mac) and can take up to at least 500 hp as far as I can think of at the moment, probably more.
Either way, I'm pretty green and the numbers I'm throwing out there I know are in the ballpark but are a bit fuzzy. If anyone contradicts me, they're more than likely right.
Links:
http://www.sr20-forum.com/all-motor/19219-motor-build-questions.html
http://www.sr20-forum.com/all-motor/17764-what-can-i-do-my-sr20de-sorry-im-new.html
http://www.sr20-forum.com/all-motor/17953-hi-port-low-port.html
http://www.sr20-forum.com/all-motor/18601-hiport-lowport.html
Also to consider, depending on how much power you're putting out at the crank, you'll want to evaluate your tranny and decide if you want to upgrade. You can put a B15 tranny with a P12 bellhousing in which is highly recommended as its pretty bulletproof as far as these go. The B13 is notorious for a weak 3rd gear and 5th gear popout. The latter can be fixed for a lot cheaper than originally feared, also another question to ask Ben about. That said, for myself, once I'm ballin' and have gone turbo, I'm dropping in a 6-speed '03 or '04 Spec-V tranny in. The 6-speed'll also do wonders if you're trying to keep MPG up to counteract performance abilities.
Some other food for thought:
http://www.sr20-forum.com/all-motor/18985-please-help-me-choose-clutch.html