Well honestly if you're going to go heavy on the mods then you're starting off all wrong. You'll want to get a high quality 4-1 header. There are headers that will easily clear even with your car so low, but they are quality pieces and will cost some cash.

The power you make will depend highly on the quality of the parts you choose. If you look around the web you'll find b16s with moderately hot cams and then some crappy bolt ons making 160-170 whp, and b16s with quality bolt ons and just Type R cams making 180-190 whp. Given aftermarket cams and good components all around I think 200whp is a reasonable goal for a moderately modded b16.