It depends how accurate you wanna go basically, I have the FX suit with a GF helmet and I'm DAMN happy with the set! To me, it's as accurate as I'll ever need, but not the case for everyone. A full GF suit, or a harder to find, TE suit IS more accurate as they were taken from an actual screen used suit. But you're paying a lot more, and have to do a lot more work. If you just want a good suit, go with FX, buy the auction Crash put up and you'll be damn happy with it. To make it even better swap out the helmet for a more accurate one and you're as good as most of the 501st guys! Fun as HELL build too, I went through mine in about 3 days and had a blast! If/when ya get a set, post your progress on the build!
frodosexual -full credit to Jeff aka creamedgeezer for that.
Grow up, shut up, and get a helmet.