Your so right John...sometimes when trying to help someone paint with inferior equipment it's like coaching a Hockey team with croquet mallets instead of hockey sticks...equipment matters and that coupled with paint designed for use on implements and not a paint designed for achieving an automotive finish, it's like Forrest Gump said about a box of chocolates..."you never know what your going to get".
Cutthroat, if your getting a Devilbus for Christmas, maybe ask for a gift card from your local automotive paint supplier as well and get the product designed for the job. I admire your tenacity in trying to make it work and I appreciate the fact that your standards don't allow for a finish like your getting, but sometimes you need to bite the bullet and invest in equipment and material that make it possible.
How does the vehicle look this morning? If you need to sand and repaint, wait until after Christmas when you have your new gun in your hand...purchase an Automotive paint. If you want a metallic paint, you need to know that single stage urethane metallic's don't have the shine that acrylic enamel or base clear paints have, it's just the nature of the beast.
If you've shot base clear with this equipment and not had a problem, maybe that's the way to go...the more information you give , the more it sounds like the material your using is not compatible with the equipment.