Are good power upgrades possible?

Hi, I am new so I don't really know how this works. Anyway, I have a 2001 rio and would like to know how to get some power out of it. Any help would be very much appreciated. I have a 3" straight through muffler that didn't really seem to do much. I did have a 3" CAI that I rigged from an Integra, but it really messed with the computer and caused it to stall out sometimes. The difference it made was noticable and sounded very good. I got that nasty recall about the fuel tube fixed, was that the problem? I think I need to get that fixed again. It is starting to miss again. I also have some performance wires and iridium plugs from NGK. The plugs work very good but don't seem to last that long. That is about it, what do you guys suggest? I would like to take this rio from 96hp to 200hp. Is it possible, and how? Also, do you guys have any sites that I might go to for racing or performance parts? I am having a very hard time finding parts for this car. Any help will be appreciated.

http://www.kia-fx.com/ for aftermarket parts.

I don't mess with mods on newer cars because I don't want to learn what is going on with this computer nonsence. But I gather from what I've read that you need to retune the engine to the computer once you have changed something. Unless you want to pay 3-5K for a reader, you'll probably want to take it somewhere for the retune. (My comp knowledge stops at troubleshooting w/ error codes, so take what I say above with a grain of salt.)