Naw, the 501st is a group (over 3000 strong worldwide now) of like-minded Star Wars geeks like me (yeah, I'm a member) who fancy dressing up in movie quality costumes - all Imperial mind you, none of that Rebel scum stuff.
Now, back to the point of this site: Like Leatherneck448 said, Bowers Tactical is a fantastic resource and I can't recommend anyone any better than them - their just good folks!