The k20 responds well but the RSX seems as the "it" car. I'd only pick one up now b/c they're discontinued and everyone seems to be moving onto the Fit and newer civics. First thing I'd do is get a base model and swap in a poor man's TSX motor.
While it is a neon, its a cheaper version of the Evo, I like to think of it as a late GST eclipse with a better exhaust note and engine. Not to mention factory backing, try getting that from honda/acura.
Redline and cobalt are the same damn thing, just different body panels and trim options, and talk about a car in dire need of a short shifter.
WRX, better backing (IMO) and better styling. It's got more trim levels for different people's life styles whereas the Evo is basically a performance car. You can pick up a WRX cheaper than you can an Evo and still kick the Evo's *** any day of the week.