I'm using aspen bedding from TSC. I can't remember the brand offhand but it seems like pretty good stuff.
Cleaning the wheels is no problem...that's what my son is for. I'm not crazy about the idea of removing them because I don't want them to become destructive. I may try that down the road if I don't get a good litter though. The noise isn't an issue because I have them tucked away in the basement below my store where nobody can hear them.