I replied on the thread you started on the rabbit forum
But sawdust isn't great for rabbits, it can harm their respiratory system and is generally messy. Blankets and towels are good for laying the base in the crate, which is what I use. My rabbit is never closed in the crate even though it is a 48inch one, but it's just somewhere for her food, water and litter tray.
Rabbits can be very expensive RE vaccinations, neutering/spaying (which is important) and if you buy rather than rescue the rabbits then be warned that they may not be dwarf rabbits for very long. There are 40,000+ in rescues
My 4 rabbits have cost me over £200 the past month for vaccinations and one of my dental rabbits (I have 2) tear duct flushing.
Main things; hay is the most important thing! good pellets but not too many, example: I feed my bonded outdoor buns a handful of science selective everyday, one of my indoor rabbits has a small handful (he is also dental but indoors after a stroke and mite treatment from 5 years in a 4 x 1 x 1 hutch... he would be dead if we didn't have him now.) and Poppy (who has the crate) has unlimited pellets but I don't recommend that of course, it is purely because she can't eat hay because her teeth are so badly misaligned
bad breeding.. another thing you can't tell from buying rabbits. She has managed to keep a dental at bay for over a year though
we have to help clean her bum though, and hopefully in the next month we will be taking on another bunny (who has awful teeth too) and bond her with him, hopefully he can teach her hay is food too
Rescue rabbits are neutered and vaccinated already and usually have a fee of £60+ for a pair which is A LOT cheaper than the approx. £60 each it would cost to spay/neuter a bought rabbit.
Whether you buy or rescue though, weigh the pros and cons. And definitely take into consideration your dogs. Rabbits can get scared and easily go into statis which, if not treated fairly quickly, can have a terrible end result.
Good luck