Rabbits are social, just like rats....they are better in pairs. I adopted my first pair of house bunny brothers about a month ago, and I can honestly say that they would be sad without each other's company.
You should look into getting an already bonded pair from a bunny rescue or shelter. It would be much easier on your part since you won't have to try bonding bunnies shortly down the road when you decide your bunny is lonely or you go through a case of "gotta-get-more-rabbits!". Bunny rescues almost always know their bunnies....then can match you up with the perfect pair of "first-timer" bunnies! They will (they better!) already come spayed or neutered also, and most likely started or are already litter box trained.
As for the cage, I personally think it will be way too small for a even one bunny. You should always give them as much space for a cage as possible. Have you heard of NIC cages? Converting large wire dog kennels to a cage? I think all pet store type cages are too small for a bun. Can you get a picture of the cage for me though?
How about keeping them in the spare bedroom? You can block off a corner with the NIC panels and gradually make it bigger for them until they have the litter box down almost completely. Is the spare room carpeted or solid flooring? Does it have a baseboard that sticks out? My room is carpeted, but the buns don't dig at it...they even have their own runner rug in their room that they don't tear at. They will, however, chew on the molding around the doors and the baseboards...so I had to cover all the exposed baseboards and moldings with fabric

.
My two buns have a bedroom much like what SOA did for BunBun, but "boyishly" decorated of course! I converted my closet into a nice big bunny room! I like them being in my closet because they have tons of space to run around, play, binkie, and do whatever they please when they need to be in there.....when I'm sleeping, going to be out of the house for more than 4 hours (for work or school), or need that half of my bedroom back for some reason.
I think you should sign up at this forum:
www.rabbits-forums.com. It's a rabbit forum, and everyone there is experienced and very quick to answer you. Never any bashing going on on that forum. It's very friendly over there!
- Amy 