You probably can do a 50A breaker and run the wall charger at 40A. However, the charger can go full 48A on 60A breaker so you will not be at full speed
The KO3 looks to be available now
https://www.tirerack.com/tires/tires.jsp?message=singleSize&tireMake=BFGoodrich&tireModel=All-Terrain+T%2FA+KO3&width=275%2F&ratio=65&diameter=20&cameFrom=selectSize&partnum=765SR0KO3