Amazon has alot of great 8in wheels, thats the minimum size mice should really having.

https://www.amazon.com/dp/B0BPS6WFFS?ref_=cm_sw_r_apin_dp_JVQ6SSK17ZGVEHYN5HAN_1

This is a super nice wooden wheel, the large would be the reccomend size if u wanna be safe and not worry about upgrading for a bit!