Yea a heat lamp and a heated rock is good. You should also have some kind of little cave thing for them to take shelter in if they get too hot, some place to get out of the light/heat. Also you could put a decent sized bowl of water in there too or work out some kinda little pond for the snake to dip in and out of. Some snakes also eat little guppies or tiny fish so you could have them swim around in the water dish.
