That cage size is a bit big and he may have trouble finding food. Its not recommended to put them in a cage that size until they are closer to 6 months. If you use that larger cage make sure to have several spots for him to find food.
OK cool I sent you a PM, just wanted to make this comment as I did not see a message in my sent box and I am a new user here so not sure if I have permissions for PMing just yet.
The big question is how long he will be in the free range, if you are leaving that up to him you need heat and uvb in both. If you keep it minimal I would not worry about either.