I've been wondering about going this way as well. The HVLP route looks good, and the Paint Shop laquers very nice, with reasonable cost. The thing I have not figured out is how much air compressor is really needed, and what the real "total" cost of a paint system would be. The $17 gun says it needs 6CFM at 40 psi, while their "pro" series guns say 12 CFM @ 43psi (for the same size gun). Presumably you need an oilless compressor to avoid contaminating the paint. What are you using? Its hard to find an affordable compressor that even gets close to 6CFM @ 40psi. HF's 6 gal/1.5HP compressor only does 3.4 CFM @40psi. They do have a 17gal/1.8HP that could just keep up with 6 CFM@40psi, but of course is more $. Are you just spraying a small area, then waiting for the tank to pump back up, or using some large compressor?
Avoid oilless compressors like the plague... they're cheaper, but they have a VERY limited useful life... A good oil-type belt-driven compressor, on the other hand, can last for decades, even a lifetime, if properly maintained (change or clean the filters and change the oil occasionally and keep an eye on the oil levels regularly).
ANY compressor can "contaminate the air" with moisture. Oil isn't a problem anyway. Moisture is. Any time air is compressed and then expands going through the valves and lines, the water in it will condense and work its way down the hose to the spray gun. When the mist blows out with the paint, it will really mess up the finish.
To avoid it, be sure you pick up one of those cheap filter/dryer setups from Harbor Freight and plumb it into your system between the compressor and the gun. It's also a good idea to get those disposable inline air filters that screw onto the base of your gun, where the air line goes into the gun... it will catch ANY stray moisture that might form in the hose or air couplers between the filter dryer and the actual gun air inlet. They're cheap and can be used for a pretty long time before needing replaced.
Of course a cheap regulator is also necessary to dial in the pressure where you want it. It's best to have the regulator as close as possible to the gun itself, but attaching it to the gun is unwieldy, so usually it's a combination unit with the filter/dryer (at least the one I have from Harbor Freight is).
You don't have to have TONS of air to spray paint... especially with the HVLP guns... if you get a detail gun, which is much smaller, you can use a pretty darn small compressor.
When it comes to compressors, you'd do MUCH better with a USED oil-type compressor than a NEW oilless one... the oilless compressors simply don't hold up. They're cheap and made for light duty, like airing up tires and balls and such... they're also not really made for "continuous duty cycle" jobs like painting, that is, jobs that use air continuously. They're more for "intermittent duty cycle" jobs...
Later! OL JR