We've got 6 different spray guns in my shop, not counting the detail guns & airbrushes. Each (whether siphon or HVLP) has it's niche: some are best for priming use only, others are good for metallics, one is ideal for high-solids production urethanes, etc., etc., but we need PERFECT results on the paintjobs we do (models, prototypes, & urethane production) so we can't afford to scrimp. A decent gun, with practice, can get you excellent results.
As for compressors: I agree with the others that buy more than you think you'll need & you should be OK. I painted my first EB, a Mustang, and a '70 Chevelle with a small Craftsman compressor hooked up to a LARGE tank (120 gallon Euclid fuel tank, stripped, cleaned, & sealed). We'd let the tank charge up to 100psi, then start spraying. Could get 1-2 coats before the comp kicked back on which was perfect timing for a break anyway. The key is constant, consistent air pressure. You really can't have too many filters & driers inline for painting, as long as you don't restrict the airflow. Dirt, water, or oil in your airline will ruin your afternoon pretty quick if it gets to the gun & onto a body panel! Good luck!