I have this
Wooden Cottage for Hamsters or Gerbils from Amazon for both of my dwarfs.
I'm no expert on them by any means, but a few coats of Plastikote on the inside (black) and the outside (Pink for Tinkerbell, Purple for Pixie), and they're good to go. They both love sleeping in them, loads and loads of space for bedding (I use tissue paper), they both spend a good 20 minutes or so re making their beds when the beddings changed over but there is plenty of space, Pixie uses half of her bed for her food hoard, so there's plenty room to shuffle and eat
hope it helps.