As I mentioned earlier, I have a '98 Lx, and I put a '00 Si rear sway bar on mine. It bolts right on, and should take you about an hour to install. All of the holes are already there, no drilling required. If you can turn a torque wrench (or a rachet), you can do this. Also, the Si bar is not too thick (I've heard its 13mm, but according to Honda's official site, its 15mm), so you dont' need to get a beaks kit or any type of reinforcement. Its not thick enough to tear your subframe. Another bonus is that you can get the Si bar for dirt cheap. I picked mine up for $80 for the whole set up (bar, brackets, endlinks, bolts,etc), and I've seen them go on Ebay for as cheap as $50. When I put mine on there was a substantial boost in the handling. Of all mods of this sort, putting a rear sway on (since you alreday have a front one stock) is gonna probably yeild the best, most noticable results.

*edit*...if you look at the picture I posted above of my Neuspeed tie bar, you can see the Si sway bar right above it