We have three does and one buck that spend all their time in wire cages. They are currently in the shed on a
concrete floor, with wood chip litter underneath to soak up urine. The feces are pretty dry if the animal is "regular" so they just build up and don't cause any problem. Our rabbits mostly
pee in one spot, so we can get away with a small amount of litter just where they pee, which reduces cleaning time. We clean once per week. We have also used dry grass clippings for litter. They work, but don't soak up as much moisture, so you need more of them/change more often. We also use a "soaking pan" of old paper egg cartons or similar material filled with wood chips. This prevents the urine from just running through the litter and onto the floor/soil. It gives more time for the litter to soak it up. Our buck pees everywhere, so he needs more litter.
Last summer we had the breeders outside on the north side of our house, just south of a hedge of cedars, with a plastic tarp over the top. It was adequate, but on dry, hot dusty days I felt bad for them. The flapping of the tarp was maddening, and put a lot of stress on the rabbits. I hope to build an arbor for this summer with a fixed roof and
trellis beans/other vining edibles on three sides. I think with adequate density of vines, this should do a better job of cooling than we had last year.
Our weaned rabbits that are growing out for slaughter are in a portable hutch on grass. We've only been doing this for about a month, and had a loose poop episode caused by insufficient fiber in the diet. Make sure the grass is either really dry and dead, or supplement extra hay/bark/twigs to dry up the digestion. Grass has too much water in it. I imagine a slow transition to greener grass would work ok, but no
experience with that yet.
Regarding sourcing hutches - we got some from a neighbor and some from the breeder we bought our starters from. None of them were ideal, but they were free. I think it's useful to get a few free designs, use them for a while, and then decide on a design for what you want to build/buy yourself. Until you have kept rabbits, it's hard to know what makes a good hutch. At worst, getting hutches for free will provide some scrap material. Cage wire is pretty expensive. You will need to do a good job cleaning any reused hutches - most rabbit keepers are not nearly as concerned with the hair/poop buildup as they should be.
I strongly recommend you buy watering crocks and J-style feeders. They save so much on wasted feed/dehydration because the rabbits can't tip them over. We buy the Fine-X feeders from bassequipment.com. They clip onto cage wire easily. Four screws and a piece of wire will adapt them to mount through a wood wall. Buy the widest size for all cages that will have more than 1 rabbit (including does). Use the smallest size for your bucks. Same rule on water dishes.