Like litlmikeyl stated you shouldn't have to worry about the hub fit as long as the hole in the center of the spacer is big enough to clear the center of the hub( usually not a problem). The wheel on your machine is mounted with tapered seat lugs and is centered on the studs, not the hub, the adaptor or spacer doesn't have to be hubcentric (centered on the hub). I prefer the machined adaptors with the studs already installed, it is much less work to install and you don't have to hunt for longer studs the will fit you existing hubs without modification. It will also save you looking for wheels with an oddball offset, a 1" thick spacer/adaptor should let you mount a bigger tire without having to worry about ant clearance problems.

OK, got some spacers and lug tires on their way. Stay tuned for photos after the install...

You may want to think about loading the tires also. You can probably get 7 or 8 gals in each one.