Can you be a little more specific about what you need?
Most of the planes are painted by the builder, some have it painted at local automotive painters. Decals are usually are available through the manufacturer, mayor decals, promark or others.
Some decals are custom jobs specifically made to scale for a certain plane. I've done decals for a few versions of the F-4 (2 of them from below for example) as well as some other jets and props. Basically all you need are some photos of the plane you want, the rest can be drawn up and printed on a dry ink thermal transfer machine :-).
Hope this helps

PS: Phantoms Phorever!