Even though there's a whole lot of aftermarket support for Honda Civics, I wouldn't suggest modifying one. You're not really gonna get anywhere unless you're pretty serious about it. Taking it to a garage to put newer parts in is just gonna cost you more than getting another car, and doing it yourself isn't advisable unless you're not really planning to drive it around for a few years or have someone who knows what he's doing help you out.
You could lurk around honda-tech.com a bit to get yourself a good idea of what comes with working with Civics, but I haven't spent much time on that forum myself so I can't tell how helpful it is, though.