That's great! I hope it works out.
Flooring really depends on the rabbit that you end up with. If the rabbit is a chewer, that can limit options. Also some rabbits are very nervous on slippery floors and will even avoid hopping on them at all. So you will really just have to see what your rabbit is comfortable with.
Hard floors are good for clean up, but the problem is that it alters a rabbits natural body position. They have to shift their weight so it's more on their back feet, and this can sometimes cause sore hocks due to the increased pressure on the heel, if they spend a lot of time on the hard flooring without having another soft option to be on.
For my rabbits I use those foam flooring pieces as my rabbits don't tend to try and chew on them. If you had a big chewer then they definitely wouldn't work. I use the wood veneer ones for my little rabbit group that has a tendency to urine mark outside the litter box, so it makes for fairly easy cleanup. Though I have had to seal the cracks where the tiles connect so I don't get urine seepage under them.
For my big rabbit pair I just use the foam tile pack from costco, then I have a microfiber rug on top of that. I like the microfiber rugs because they have a very soft surface and aren't as abrasive to rabbit feet(help prevent sore hocks) as other types of rugs. If you use a rug, just make sure to use something with a soft surface.
Fleece fabric is another option, though it will tend to slide around unless you have a way to secure it. Vet bed with none slip backing would also be an option, though it is a bit expensive.
But the problems with using rugs and other soft things for flooring is that some rabbits LOVE to pee on soft things. They may also try and chew them. My rabbit pair has a rug because they don't pee outside the litter box except for the occasional accident. My little rabbit group doesn't get a rug because they do pee outside the litter box. So the foam flooring gives them a softer surface, but is urine resistant. I do give them pet beds to snuggle up in, that I just rotate out and wash as needed though.
You'll find that finding the right set up for your individual rabbit, takes a bit of trial and error. I don't know hay many different flooring, litter boxes, arrangements, hay holders, etc, that I've tried until I found just the right one or situation for each rabbit. I hope you don't mind spending money