Unless house rabbits have a dedicated room, an x-pen is a great way to provide your bunnies with a personal safe zone. X-pens can house their litter box, food and water dishes, as well as hiding places and stimulating toys. In Lethbridge, we purchase our x-pens from Petland, typically the 36" high ones with a door.
We create litter boxes for our rabbits by using a base layer of hardwood pellets with a layer of hay over top. Hardwood pellets can be found at Canadian Tire, stacked on pallets. If you're asking an employee where they can be found, these pellets are typically used for fire fuel.
Pellets should only comprise 5% of a rabbit's diet. We recommend the Oxbow brand from Petland, PetValu, or Homes Alive. If you prefer to stock up with the extra large bags that we use (and supply for fosters), these can be purchased from Trouw Nutrition for about $21. They last a long time for a single rabbit!