I have a 2000 B2710HSD w/R4's and want to change them to turf wheels/ tires. I understand that I have to change both the wheels and tires but I'm having a difficult time finding the part #'s for the turf tires/ wheels. Can anybody help? Also, do I have to buy them from Kubota or does anyone know of a company that sells equivalent tires/ wheels for less $? I'm willing to buy used! Thanks!