id say go paint. you get a larger variety of colours etc. and as its already been said its easier to touch up if you get scratches etc.
heres a set of regamasters i had redone a while ago.
with regards to the op painting centres, are they 3 piece wheels?
if they are i wouldnt powdercoat them unless you take them apart first. as powder coating gets up to like 200degs and will mess around with sealant and glue etc holding the wheel together.