Oh last thing:

If single color NON-metallic, use single stage urethane paint, shop lines seem to work fine. If metallic or pearl is involved Base Clear is mandatory.

If you are doing this on the cheap, don't waste money on high end materials, don't be scared of cheap materials most shops are using some sort of cheap line stuff for production vehicles anyway, talk to a local shop ask what their cheap line is and go with that.

If you are really particular on base coat color, pearl color/appearance, or metallic size/distribution/look, then you should get someone who knows how to spray base coat (some metallics and pearls are hard to get perfect) and have them bring their Base Coat gun, let them spray the base, and purchase higher end base coat materials and reducers. If he knows how to spray base let him spray the clear too!

Cheap out on the clear if you are tryin to save a buck as long as its urethane, let it eat.