I only have 3 mice right and don't think that we need to go higher then 5 f. They are in a x large wire hamster cage. they have a wheel and tubes to hide in. might have to use a bin as soon as my snakes need a larger then fuzzy as they might excape( we just started to breed them).
I'm still kind-of old school with my mice. Ten gallon tanks as far as the eye can see, from floor to celling. I suppose I should start to think about racking them. I have Freedom Breeder racks for my snakes and I hear they make great rodent racks too.
The shelf system was from Lowes' years ago. I think home depot, menards and others like that have them now. They are really nice and sturdy. You can place the shelves pretty much where ever you want.