one thing i forgot to mention that you can do when you get to the more expensive mods
is the intake manifold - you can bolt on the Civic Fn2-R intake manifold (RRC) for a descent gain
again skunk2 make a nice unit as well - both can be pricey and they are a bit of a pain to fit
usually people put in the hondata intake manifold gasket and the USDM V6 throttle body to get the most out of this mod

RRC manifold


Skunk2


Hondata gasket