Bunny’s shouldn’t really be housed in cages. The best options are x-pens or free-run. X-pens are those puppy exercise pens that are used for young dogs that need to be confined in a smaller area. These are great for rabbits, as well. You should use laminate or another cheap, durable flooring to protect the floors and perhaps an old sheet to cover up the flooring. (Rabbits like the softness of a sheet, we like the protection of the flooring.)
Free-run is the best option, with x-pen as a close second. Some people keep their rabbits in a large room such as a living room with a door or somehow otherwise closed off. You’ll really need to bunny-proof that room, then.
You could also have a mixture of both. I have a friend who has a pair of rabbits who live in an x-pen in their game/entertainment room and the x-pen door is always open so that the rabbits can come and go as they please.
In my opinion, the x-pen is the best option. It’s spacious, cheap-ish, and confined. The size for two rabbits would be 8-10 24″ panels, with a height of 24-36″. Just put down the flooring and cover and add litter box, toys, and hiding house as well as hay, pellets, and water bowl/bottle and voila! A beautiful rabbit cage.
Here’s some bonding tips from the HRS: http://www.sandiegorabbits.org/behavior/bonding-tips.html
Good luck!