i would advise to go for a primer if your trying to get a good look out of it. but make sure the primer is a high temperature pain. most shops sell high temp paint but high temp primers are hard to find. if you don't have to paint your heat sinks i would advise not to, because most shoudl be specifically engineered to dissappate heat well, and paint could some what bother your amp's ability do dissappiate the heat.