I'd wait until I could afford a K-series K24(from a TSX) or K20a2 or K20z1 (from a RSX). Otherwise I research research research research. Then talk to a lot of honda lovers and the Mechanically inclined. Ask what they did and what they wish they hadn't done to there cars.

What do you want to do with your civic? Example of set ups: quick daily driver, Circuit racer, Drag racer, show car, or noise violater.