for painting you dont need a huge compressor a 5 hp 20 gallon tank will do just fine, spraying paint does not require the huge CFM that say an orbital sander or sandblaster need to perform ,you will be using low pressure and low CFM to spray paint and primer.
As far a spray gun for primer , por15 etc ...ya dont need to break the bank either ...check around Summitt, Eastwood and lottsa others sell guns some times 3 in a kit ...1 for primer,1 for paint and a touch up gun at a really good price.
You stated you would like to use tools with your new compressor , now that is a different story ..all depends on what and how often you will be using , if you are gonna use a lot of air then a 220 volt,2 stage 60 or 80 gallon tank compressor is what you want .
Just some tips
