the fronts wont make much difference, just use what everyone else does: maxxis razr 2's or whatever holeshot front is popular in a 21 or 22 inch.
on the rear, i'm a big fan of the holeshot xcr's for these smaller quads. they are a hair shorter and a hair narrower than a normal tire in the same size, and i think on the little quads that those are benefits. They are a little lighter which frees up a little horsepower and they dont have quite the grip the bigger tires do, which means the tires will spin a little easier. that was a big benefits for me since I like to ride a little high in the rpm's, less grip helped keep the revs up
same as the big quads, 9x9 rears and 10x5 fronts in 4:1 offset. use what ever offset on the rear that will make it equal the total rear width equal the total front width. If it wont match exactly, i prefer using the offset that will make the rear narrower than the front so you wont hang on trees as easy