Well, we are in the process of setting up a Foundation modelling team, in order to update the Default/Sample Asset pack, and to put some models on the Marketplace, once it goes live.
Funnily enough, one of the things I've put on the task list is a rabbit. Unfortunately, work hasn't actually started yet, because we're still busy working on other things with more of a deadline.
However, I will be restarting the modelling team project in the next week or so, once I've sorted out the website.
I did just do a search on TurboSquid, but the free/cheap models are all cartoon rabbits, unfortunately. I'm sure you already checked though!