Use caliper paint for the calipers. Duplicolor is readily available at parts stores. There is also g2 you can buy online. Have heard some good things about it as well. Can use both for the hubs as well. Clean and prep is critical to get good finish and adhesion so it last like it supposed to.
Valve cover you can use hi-temp engine paint. Several diff brands available such as duplicolor, rustoleum and vht.
Color is up to you but I personally would stay away from white. My car is twilight blue and I'm gonna do my calipers red but the other brake parts black. My valve cover is painted black with red.
Hatch Nation #9
"2 by 2 Hands of Blue."