[Nezu]

I had a friend that had a bunny and ferret. He had the train the ferret at a young age to get along with the bunny. Also because the ferret was female it supposedly was less likely to hurt the rabbit. As an extra measure they were always supervised when in the same room and usually they were let out at different times. If you decide to go through will it I would introduce the rabbit to the ferret in stages so it can get use to it. I would advise against having both though.