Nothing bigger than a 6 quarts or 15 quarts tub.
Aspen Bedding
Plastic Flower Pot Saucers (6 inches in diameter) 1 or 2 depending on the tub size.
UTH
Thermostat
Water Dish
Thermomether / Hygrometer

Once the animal is bigger and eating for you, you can consider a larger enclosure (plastic, glass or cage)

Do not buy food in advance, ask the breeder what the animal is currently feeding (likely live) and feed the same prey items that were offered before, once the animal eats for you (which is the hardest part for new owners) you can consider switching prey type.