Arctic Cat 300 4x4 help

I want to give my quad some more power without spending alot of money, any suggestions? I am about to replace my tires as they are old titan 489's front are at24 x 9 x12 rear are at25x 10 x 12. I want something that is great in mud, snow, as well as hard pack trail riding, and will not affect the machines performance in negative ways. I drive about 1 mile on the blacktop to get to my destination which has alot od mud, as well as sand, woods, swamp, train bridges, etc...Any and all help welcome. What do you think of the 589's/ Should I get the same stock size, if not why? Is it possible to get as good as traction and power in mudholes as my brothers Vinson 500?