Congrats man.
Are you planning on building up your DX?
If you are concentrate on opening up your exhaust system. The exhaust system on a DX is really "clogged up" and completely different from any other model civic. I'm talking about the exhaust manifold, cat, and exhaust. Mabye go Header(for an ex) w/ an aftermarket cat(for an ex), and then an exhaust (for an ex). Other than extending the O2 sensor wire, I think it's pretty straight forward. Might be some custom fabrication needed on the exhaust.
Someone should probably check me on this.
HIH