Just picked myself up a new 2012 Polaris Sportsman 800 before Christmas, figured there must be some Quad enthusiasts on the board.
Just picked these up and got them on today,

Polaris Wrec rims with 26" Ripsaw tires.
Also ordered a bush guard and am looking into a viper winch.
And just for the sound I am gonna rig up a magnaflow muffler since from what I have found online they have a nicer sound then the slip ons.