If I had that kinda cash and was looking for power, I'd look into head porting as well as slightly more aggressive cams, a new intake manifold/throttlebody (like you mentioned) and I/H/E. This should give a nice, all-around power gain. However, that's me and I'm not much on drag racing, I'd rather carve a canyon If you want power that you can turn on at the track, own a bunch of other hondas, and then turn off and go home, nitrous is the way to go.