Fillet of trout, salmon and tilapia are the best as far as, well, fillets go. Guppies, and silversides are also good.

Don't spend a ton of money on tank items, all they really need is some bedding, a few fake plants from the dollar store, a little hide, which can be as plain boxes if you wanted them to be, water dish and heat, like Stefan said.

Edit:
Keep the substrate dry, do not make it damp at all. It can harm Bunny and give her scale rot. Use a bedding like carefresh, shredded aspen, or something close and she'll be fine.