There look to be plenty of spares/upgrades for the KV-1, including a KV-2 turret

T34 seems to be a new model, so should avoid some of the design problems? But can't see any significant upgrade or spare parts. Do the larger road wheels cope with grass etc better?
Also not looking to do too much repainting etc for now. Used to about 20-odd years ago, but more interested in using & tinkering for now.