A Google search Provided this link. http://www.thomasnet.com/kentucky/po...2441357-1.html
Some of these may only service commercial accounts and some will do work for the public. Some may not have the capability to handle a frame.
Remember that you have to have all welding' fitting and grinding finished before powercoating. It is also a good idea to have it as clean as possible meaning, no grease or oil. Most power coaters will have a sandblast room or a connection with one.