If you're thinking of respraying your alloys, don't bother, it looks awful, can chip and flake, won't last and to do it properly takes ages. Better to take the wheels to an alloy wheel refurbishment/repair shop and get them glass bead blasted (not shot blasted which will blow holes in the alloy). Finish with a coat of lacquer or if you want a colour rather than the bare alloy get them powder coated.
snags, You may have this wrong, if you the job of rubbing the wheel down, put on grey primer, then rub THAT down, re-prime & finish off with the prefered silver that you can purchase from any Auto spares shop, I bought a BBS Sports wheel a while back, it was in a right state, I done what I have posted with good results, that's my opinion.