15x8s will hold the bead better, they will make the tire appear a biot taller. 15x10s will make the tires stick out of the wheel well more. This can be good and bad. It make tires appear more aggressive but, if your local badgeflashers frown on that, they will be constantly hasseling you. The 15x10s being wider will also have your rim bead eadge sticking out more where it can get more trail damage.