I had the exact same problem. Fridges in this building can't be over a certain size(5.0, I think...).
I'm using a Magic Chef(like the one southwind mentioned), but mine's a 3.5 cubic foot model. The freezer is in the top and has a separate temp control than the rest of the fridge, the freezer can hold quite a few boxes of large mice.

It works like a charm, unfortunately I can't recall the price, although it's probably a Wal-Mart buy.