i used to make ornamentaly railings and fences, my boss had a GOOD airless sprayer, just a hand help jobbie it was german and about 4 or 500 bucks he said, and man it was finiky it paint had to be the JUST RIGHT thickness, and if there was ONE piece of crap in there, STOP and tear down the gun.
it has just as much if not MORE over spray, and in the middle of painting if it wanted woulds start to spit paint in gobs at your work, not so good if your doing a truck.
if you dont have a compressor and dont want/have the coin to.
maybe look into a turbine air system, it is a low Psi ( reallow) high volume air sprayer, uses a box with a fain in it, and the ID, of the hose is about 3/4" has good controle adjustable fan, and low overspray
dave