Lee - I was thinking about that also, but they are 15" wheels.
I went to a local media blasting place today and the guy was very informative. Not to mention the DIY shop rates seemed really cheap. If you use one of the cabinets it's $12.50/hr and if you need the blasting booth it's $17.50/hr. If you pay them to do the blasting, it's $45/hr.
Anyway, he said you can blast off the powdercoating. It just may take you an hour per wheel to do it depending on the quality of the powder job.
If anyone is in SW-MI check out
http://www.consolidatedstripping.com/