Recently picked up a set of Epsilon 3-piece wheels. They're in great condition but I will be re-finishing the centers and buffing the barrels up. I'm considering having the centers powder-coated rather than painted. Thoughts? Recommendations?

The cast aluminum they used back in the day wasn't as pure as it is now and it can out gas while the powder is melting and cause bubbles.  Just ask your powder coater to throw your pieces in the oven with other stuff he has so it can go through a few heat cycles before he coats them or you could do it in your own oven even.