Kyle used to have an indoor meat rabbitry, so I know he could give you some tips.
It did have a lot of advantages and disadvantages!!!
Solid bottoms are a bad idea especially if they are indoors...there's just less air movement, so pee will stay wet longer, and the filth is bad for them. ESPECIALLY if you make the floor of wood...wood is porous and will hold bacteria and nastiness.
I would not do solid three-sides. Two sides solid might be okay, to prevent spraying, but honestly not all bucks spray so it's not that much of an issue. With the cages you described, air quality will be a problem. Indoors, there's no air circulation without fans, and unless windows or doors are open to the outside, it circulates the same darn air. :x Wire, wire and MORE wire will help keep them from breathing nasty fumes!
The best part though is that they are RIGHT THERE. No slogging through mud and rain to go feed on a stormy day, the basement rabbitry I had stayed nice and cool all summer so heat wasn't an issue. No rabbit ever got a sun-kissed pelt, LOL. It was nice. But the air thing was a constant, CONSTANT struggle. Wire floors, drop trays about five inches or more below the cages, and trays emptied every other day. Apple cider vinegar seemed to help the urine be less reeking and cut the ammonia in the air. A fan on a low setting to circulate air 24/7 was also a must.
If you are worried about their feet, as someone else suggested, get resting mats. But better yet, check over any potential breeding stock for the right feet...wide feet with good fur are not likely to get sore hocks on wire. Skinny or long/narrow feet without a good fur base will be a problem. If you have a line that has genetically appropriate feet, go for it! SOLID floors are more likely to cause sore hocks...the feet get wet from pee, and it irritates and damages the foot, and since they stand on that the damaged area ulcerates and bam, sore hocks. Almost all sore hocks I've seen? Rabbits on solid floors. You can't clean the floor often enough to protect them.
Did I mention air, and more air?
An air purifier was being planned for before my life kinda fell apart, that would help as well.
And wire. WIRE AND AIR, I can't say it enough. :lol: Wire allows air to move through. Solid walls/top/bottom will get a lot of respiratory problems.
Scattering some carefresh or pine shavings in drop trays helps to absorb pee so the air is cleaner, too. Indoors it's a huge help. I don't bother now that my rabbits are outside.
ON WIRE, all on wire.
Wire floors. SRSLY. I had a solid-bottomed floor for a while, it was a NIGHTMARE. Horrible, horrible!!!
