For spray gin, definitely a filter. For the moment disregard whatever ambient temperature or moisture is in the air. You're going to have condensation from heat and cool down cycling from the compressor operation. I'm guessing you have an oil less compressor, but if not, you need an oil separator as well. Also, if spray environment has higher humidity, you can adjust by using the appropriate drier additive to the mix.

+1 on the HVLP mentioned above. They need big CFM to use. However there are 'hybrid' versions (gravity feed / HVLP) that can operate off lower CFM.