Mugsy,
I'm no expert but I'll share a couple of thoughts. First, you'll use lower PSI when painting and higher PSI when media blasting or using air tools. You'll want higher CFM if you're using air tools that will run more than short bursts (like media blasting). While horsepower may be important, I think the tank size is more important. The bigger the better. I think the bigger tank supports more CFM. I'll take the back seat and let the experts take it from here. I currently use a 6hp, 80 gallon tank and it's great.
Jerry
