Ok, ok. I must admit, I'm the Old Milwaukee beer drinker of the group. And when it came time to paint my one (and possibly only car - bc/cc), I did a ton of research on paint guns, HVLP guns in general. I could've spent several hundred dollars on a gun, but decided to go with an Astro (HVLP) gravity feed gun - It cost under $100 and did an exceptional job. I used your standard craftsman 30 gallon/5hp compressor and built a custom 3/4" copper line with several in-line filters. One of the best tips I was given was use about 50 feet of hose (ideally, you might have a secondary air tank between your compressor tank and your gun to achieve the same goal) coiled up between the compressor and your filters (BTW, I used a toilet paper-style filtration system - much cheaper than the desicant units). This keeps the humidity and moisture from ever reaching your gun. Oh yes, and use a small, in-line screw-in filter at the bottom of your gun. I painted my 68 HT in July/August '98 in my garage in Dallas - no problems with moisture.
As far as the Astro goes, I think the are designed identically to one of the famous HVLP paint gun makers out there. I can't remember which one. There are many tips and accessories also available for the Astro.
No matter what make you chose, go with a gravity feed HVLP. That's what all the pros I know are using. And remember, good air filtration is key (along with the correct paint tip choice - but that's another school of hard knocks!) Good luck with your decision and let us know what you decide.
70 Mach 1 (351C 4V 4-speed) I've been restoring since '96. 95% complete. Also have a '68 HT (289 2-speed) that I restored between '97-98 and is FOR SALE! The VMF has proven to be an invaluable resource for information, humor and excellent advice.