Thats true HydroGTI. I think I would regret not buying the GTI.
Agreed.
The GTi's gonna be a funner car, in my opinion. I actually looked at a Honda Civic Si for a while myself, bro (the 06-09 body style, I assume?). There's only one problem with that in NC (and everywhere else, I'm sure): EVERYONE DRIVES THE CAR! Also, I've been reading a lot of blogs and testimonials, Civics are common place for modding, so you may end up attracting a lot of unwanted attention as well.
http://www.autoblog.com/2007/11/15/2008-mugen-edition-honda-civic-si-vandalized-on-dealer-lot/
Not saying this'd happen to you in your area, but you never really know, since now almost every thief EXPECTS a Honda to be modified, or have some goodies if its on the road, now-a-day. Don't miss out on the stats, though. The new Si have the 2.0L DOHC I-VTEC KA20Z3 engine, which not only has a good compression ratio, but a second cam set which engages at like 5,800 RPM (my theory is that the engine was modeled after the Toyota Celica engine, which, is basically a Yamaha Sportbike engine, if I'm correct). I've been out on an interstate-run in one, and its really sings when you need to get infront of and just absolutely leave traffic. With the right mods, you can make it a beast, some FL-baddies are starting to get popular on youtube, mind you. My only beef with the car, is that its too popular, 1, and 2, the engine bay is HORRENDOUSLY cramped. But I'm sure you can manage to fit a turbo or supercharger in there, whichever your preference.
Then lets move onto the GTi. It, like the Honda, is a good car. I've seen only a few around town. They're slick, and they come with turbo's stock (but obviously you know that). Its hatch, which is a plus one in my book, and ontop of that, it just looks pretty damn good. Going with either 2 or 4 door shouldn't matter, cause the drive will still be fucking fun. If you're intent on modding, nothing beats a car that looks fast, but completely blows the opposition away, because its actually even faster. I don't know much about the engine, other than its already turbocharged with 200hp, so it can handle the stress of forced induction and the hard driving, I'd assume.
Either way man, its up to you, but I have to side with Hydro; you'll probably want the GTi in the end, anyway.