I have a 6.5 hp Campbell Hausfeld with a 60 gallon tank. It has enough presure and flow for what I need but the piston type makes a lot of moisture and requires a good filtering/seperation system. If I was loaded I would have bought a Kaeser 5hp screw type with seperator/chiller. But that stuff gets $, screw types are real quiet too. You would probably be good with 5-7 hp piston compressor, pay close attention to the flow rate at higher pressures, relate that info to the tools and thier requirements that you will use most.