Spray gun is the least of your concerns as they take little pressure & low air volume ...
High air volume is needed more for sanders, blasters, grinders ...Do you have 220 volts available? A 2-stage is best but if that's not in the budget get a single stage with as large a tank as you can find. Check Tractor Supply for a good deal in a single stage 60-gallon, locally they get $399.