I've been using good old exterior latex house paint for a while now. Great durability and is impervious to gasoline. Glow fuel will
react to the latex and a clear polyurethane or enamel needs to be
used. This stuff sticks to fabric covering well, too and since it is a
rubberized paint, it isn't affected by the expansion or contraction
of the fabric and is very durable. A special technique is required to successfully paint with latex. Click on the link below to see a
very good process I found in Model Airplane News a while back.
This way of painting is also very inexpensive. A quart of custom-
mixed paint will only set you back 8-12 dollars and that's enough
to do a few planes. If the following link doesn't work, go to the
M.A.N. website and click the "how-to's" link. There you will find this
and many more good tips and tricks that really work. Good luck.

http://www.modelairplanenews.com/how_to/latex1.asp