A 48 x 24 x 24 inch cage would be appropriate, The absolute smallest I would go is 36 x 24 x 15 inch.
Here is an old picture of my carpet setup before I moved him into his adult cage. This is half of an animal plastics T8 (48 x 24 x 12 divided to make 2x: 24 x 24 x12 inch cages)
Last edited by The Serpent Merchant; 04-12-2014 at 11:58 AM.