Sandblasting Callipers?

The brown man delivered my wj callipers today and they are very rusty. They came from the north east, forgot where. Can I have these sand/media blasted and maybe powder coated? What do I need to do to them first?

Just dont get the cup or seal. And make sure to plug the line and bleeder holes. Ive done it before, and just did some hi temp engine paint.

Plug the following (at least):
Piston Bore (at the surface. Oddly, a suitable cork should work well, provided it don't come loose.)
Line Attachment Hole (Find an SAE flare plug. Don't just use a flare nut, you'll get crap in the caliper.)
Bleeder Screw Hole (if you've got an old bleed screw you're not going to put to use, perfect.)
Bores for the caliper pins (it slides on these, and you don't want to screw them up.)

Also, mask off where the caliper slides against the bracket. Scotch-Brite will work well for those - or very fine media - you want just a hind of texture there to hold lubricant, but not much more than that.