You'll be lucky to gain 20HP max at the wheels with I/H/E/IM under perfect conditions. If it were my car, I'd start by doing head work.
IMO, if your planning on a swap, stop throwing money @ your current engine & start saving for the new engine. Invest money into suspension since it's one mod that actually does something for the money.
http://www.mmrusa.com/gudehead.htm
http://www.importreview.com/performance.html