help in compresser size

i need a comp. i'm starting the boby work on the duster this spring i'd like to know what size to get it's not to paint but would like to run some air tool's and prime . What should i look for, i'd like something i can move around for ex. part store here has a 8 gal. plus air gun & rachet ect. on wheel's for $ 199. would it do, i know buy cheap get cheap or should i look for something bigger if i talk to a sales person he'll say bigger for buck's but i'll talk to the one's who really use thank's for your input