There's no trick to bead blasting provided anyone has the right media! I should think any good machine shop could do it. Heck, you could rent one if you have an air compressor!
FYI - Check out the link below. It'll give you an idea of the various media available. I expect you'll want Acrylic or glass beads.
http://www.kramerindustriesonline.com/blasting-media.htm?gclid=CLLh3-GZk8YCFc5ffgod7WQACQ