I would say stick to NA. I've road raced my car NA at Texas World Speedway and it was an absolute blast. I'm turbo now but I won't take my car out on a big road course. When you go turbo, you basically need more of EVERYTHING! More cooling, more brakes, more tire, more clutch, etc. Plus, if you're just looking to improve your skills, more power won't help you; it'll probably make it harder actually. When you start out, you just need to concentrate on driving the correct line, hitting you marks and braking points, work on the downshifting, and consistency. Oh yeah, my LSD has gone to crap, I'm sure the turbo didn't help that

If you need max reliability, stay away from the turbo. More power = more stress = things break faster (well, axles and trannies at least)!
I'm actually thinking of converting my car back to NA once I retire it from daily driver to road course slut
