Myself and a few others have used the "G2 paint kit". Just do a search on eBay or Google for "G2 paint" and you'll find tons of dealers. It's basically a two-part paint that you mix together and it hardens within 4 hours. Just to clarify, you might get the calipers painted in two hours, but you've still got to let them dry overnight before you can drive with them. I think you've got to wait at least 4 hours before reinstalling them on the vehicle, but I would just let them dry completely while everything is still apart.
I think www.tirerack.com is one place that sells these kits.
Calmini Cone Air Filter, PowerVault PV2 Muffler, OME Trooper Springs, Rancho RS9000X Shocks, 285/75R16 Nitto Grappler AT's, Pioneer DEH P8000R In-Dash CD, Amps and Drivers Built by Orion, Wires and Fuse Blocks by KnuKonceptz, Vibration Damping by BQuiet, Alarm System featuring Auto Start and Remote Windows, Yakima LoadWarrior w/Full Size Spare, Debadged/Custom Titanium Grill Logo, Tint (5% Rear / 20% Front), Steel Braided Brake Lines, G2 Painted Calipers