Save yourself the headache. Spray painting ends up being alot thinner cover than powder coating and ends up being less chip resistant. Besides, sanding the frame can be a real female dog. It's too time consuming and there are places on the bike that are hard to access (like the bottom bracket area).
Just have a reputable paint company powder-coat it for you. Alternatively, you could rent the equipment and powder coat it yourself, after having it professionally bead-blasted.
Whatever choice you make, make certain that you rustproof your frame after it has been bead-blasted.
Happy Trails...
PS.
Powder Coating is best suited for bikes.
Last edited by SlimRider; 08-18-11 at 12:47 PM.
Reason: additional info added