I'll be replacing all four tires on my SPF Cobra in the next couple weeks. The Eagle GT IIs on there now look the part, but are basically crap IMO.
I had
posted a thread about 15-inch tires options which you might want to read.
In the end I've decided to go with the Cooper Cobras, which are basically the same as the M/T Sportsman S/Ts.
A lot of the responders to my thread prefer the Avons, but distribution and costs are much worse in Canada than in the U.S. so it would be a hassle and very expensive for me to go that route.