i vote powercoat.
If you paint them do it if you were going to change the pads anyway; pull the calipers all the way off, clean with brake cleaner (likely will use 1 can on each caliper depending on the last time you cleaned them), rub with isopropyl alcohol once clean, paint without the pads in, use 2 -4 coats of clear, and you're good.
In my opinion of the caliper covers (and not to flame) is they look too big for small brake pads once put over stock calipers. Some people like that look, most don't. It's your car do what you want. Only here you're gonna get flamed for it, i'm sure everywhere else you generally show off your car you will turn heads