I'd go for at least a 20L display. Even younger BPs need relatively large hides and water dishes, which you'll have trouble fitting in a 10 gallon. The price difference between them, including the extras like screen tops, clips, lights, etc, isn't too bad, and it will last longer.
If you go with a tote instead of a tank (which is probably ideal as Adrian said, since it will probably feel more secure there than in a big glass box), check Bed, Bath & Beyond for some of the better quality totes with locking lids (I think they're Iris totes, but I can't remember for sure). You can use a soldering iron to burn plenty of airholes in it without leaving jagged edges.
Not sure if you have any heat sources yet, but check the clearance shelves at Petsmart for their All Living Things habitat kits: I bought a couple of them for 7.99 (marked down from $28), and they come with either a UTH or a lamp (depending on whether it's a snake, bearded dragon, tree frog, or other kit). That's the least expensive UTH I've found by far (next to buying flexwatt and wiring it yourself). A rheostat or thermostat is a must for running a UTH...I started with the rheostat since it was cheaper, but now I have a thermostat and life is much easier.