If you're in Austin, I can highly recommend CMT (Consolidated Metal Technologies) in Round Rock.
www.cmtfinishing.com
We use them on average about once a week mostly for anodizing/electropolishing/various other plating but have had several things powdercoated over the years. We have been using them for about 7 years.
They do solid work and have a quick turn. Call and ask for MaryAnne, she'll hook you up with a quote.
Oh, and just pull your wheels off, run them up to a NTB or Discount, have them dismounted. Then run the wheels to powdercoat. When they are done, reverse order. Ehh, its that easy.
BTW, I thought I read more than one thread about how calchrome was ripping people off on that wheel exchange crap. Could be another company, idk. But dude, its stupid to ship your big heavy wheels to freakin cali to get powdercoated. Theres is PLENTY of places to serve you in the Austin area. If you'd like more references on good plating/powdercoated shops let me know... We have experience with more than a couple. I just posted CMT b/c they do the best work out of all others I know.