Sorry I can't really answer your question because I have mixed bunnies and don't know much about breeds. I think lops are pretty mellow but I'm not sure about mini rex bunnies. I bet you can find info online about the different breeds. You could also go through a rabbit rescue and they could help you pick a bunny because they usually foster the rabbits and know their personalities. Do you want a purebred or do you just want a laid back bunny? There are many calm mixed bunnies out there too, but if you like purebreds you could talk to a breeder and maybe they could help.

Sorry I don't have more info.