Well I think lop eared bunnies for the most part seem to be very nice. And darf bunnies are more aggressive but it really depends on the rabbit itself... I have a darf and a mixed breed and my mix breed is friendly. I also have another mix breed female and she uses a litter box or atleast she used to. Im sure you could train any to use a litter box but you need to spend alot of time with them.