They wont be ever left alone together, I do realise there completely different species and do not mix. I have scratches all over my hands from him I'd never put my rabbits at risk of that!
The only reason I'd like them to live happily together is when the cat goes outside, his cat flap will be in the room next to the rabbits, which has patio doors, so he will be able to see in to the rabbits and the rabbits will be able to see him.
I'd just like to be able to go to work in the morning without the fear of the cat being sat at the patio door all day traumatising the rabbits!
The rabbits have their own room, the cat never need even go in there and he wont as that is their territory.