Thanks everyone for your advice.
Unfortunately I'm not able to do much at the moment, all the money I had saved for their new aviary set up has to go on repairs and I'm left with about £50 until at the very least the end of the month, so there's not much I can do. My house is tiny and the only space I have is in my bedroom, which is pretty much my dogs room at night. He has arthritis and neurological problems, which means sometimes his back end doesn't keep up with his front and he'll just flop over regardless of what's underneath him. Although he's brilliant with the rabbits, at night he gets very disorientated which is why he has to stay in with me, and I worry if the structure isn't strong enough (e.g. puppy pannels, c&c cubes, or even a cage on the floor, hence the need for a stand) he'll squish it, the only thing strong enough is a dog crate, (which I can't have as he's terrified of them, as he lived in a tiny one for the first four months of his life) and I certainly can't have the rabbits running free when he's around.
By the time I squeeze in my dogs' massage bed, bowls and hoist I have a ft gap between my wardrobe and desk, I don't want to be cruel of course, but my dog has to come first and with all his health needs if the worst came to the worst, he'd never find a new owner, if I can't do right by my rabbits, I may have to make the awful decision to find them a new loving home, but I just love my girls so much.