when i lived in the UK hagon laced me a set of rims, you can run a 160 rear tyre with no probs i only run the 180 for show that and i used to use take offs from my race bike for my older GS12 the K rear wheel wont fit, its the wrong way round and the off set isnt right either, as for fronts if you just want to do hill climbs (man i miss those) you can get sum pretty good rubber in a 19 wich will work ok but it wont be race rubber!
i did alot of track days on my 05 GS 12 it worked pretty well but it had a host of other mods too
