Picked up a set of near perfect Tundra 18's locally for $200 today. They match what is already on the 100 and will allow for common spare(s).
Also ordered some 5x150 adapter/spacers. These will push the wheels outboard which I hope will add to stability. Once I get the wheels/tires/spacers in hand I'll figure out what exactly is needed for lift (SOA vs shackle) and go from there.