Just beware. The reason I do all my sandblasting myself is because I DID take it to a professional sandblaster. I expected completely bare metal and what I got back was greenish, splotchy and had areas where paint wasn't completely removed. I paid ALOT so that was that. I did some research, got the equipment I needed and now its just a distasteful, miserable week or two. Not all that bad really in the long run.
http://speedprint.com/deves50/sandblasting.php