ya the si is like 110 hp i think. i imagine the main difference in the power output comes from a higher compression ratio and a more aggressive cam, but i really dont know. theres tons of options for your car. the most popular are the zc swap, which is pretty direct i think, and the b16 swap, which requires mounts and some other stuff if im not mistaken. then ofcourse you can pretty much swap in any engine or combination of engines from any of the civics up through the 6th generation. so you've got lots of options.

the important question here is, how much are you willing to spend, and how fast do you want to go?

check out hmotorsonline.com or some other importer for prices on jdm engines. or just check ebay and classifieds for miscellaneous options.

btw im no authority on 4th gen civics, so im sure someone will chime in with better info.