The bigger the cages the better. They need space to move around and stay healthy. I would not use wire bottom, it really hurts their hocks. They dont have paw pad like dogs and cats, it's just a thin layer of fur. Especially with rex rabbits.
@Compost King knows what wire is best should she use wire.
Though they will live out in the weather ots best they are protected from it. If it's hot they should have lots of shade, fresh water, and a fan (though a fan is not a necessity). In cold weather (which they can tolerate much better) heated dog bowls to keep water from freezing is important. They drink as much water as a large dog. Water bottles dont provide enough and they will freeze. Fleece blankets are great all times of the year. They love to dig in them and it's safe to chew.
Of course they'll need unlimited high quality hay all the time. Space to move around, at least stand up, and jump at least across two sides. Good nesting boxes. And lots of things to chew on. I'm going to make a thread with DIY rabbit toys ideas all out of cardboard, twine, paper rolls, and paper bags.
Other than that they'll need regular grooming and check ups. It would be great if they had a playpen that they could exercise in.
And a lot of people keep the babies inside. If that's possible that would be great bit a lot of people say they do fine outside. It's kind of a controversial topic, but in my opinion it's better to be safe than sorry, so I would keep the babies inside until they're healthy and strong.
Are these going to be for meat?
