Tires and rims for 570 eps

Just picked up a new 2016 sportsman 570 eps. Looking for some new tires and rims. Want to go a little bigger then stock but don’t want to do any mods. I will be mostly riding trails some mud and snow. Not sure If I should stay with 25" or 26" 12" or 14" rims also would like to get a radial tire and smooth ride. Where is the best place to buy already mounted. Also would would like to stay under $900 otd. Thanks in advance.