I'd agree that when you make housing decisions for your snakes, Rich at Reptile Basics is your new best buddy. Give him a call, describe the setup you are intending to use and he'll likely have a good, cost effective heating option to offer you. His shipping times are insanely fast so there's no sitting around for 3 weeks hoping your stuff will actually show up.

I like to offer our boas a good deep substrate since they enjoy burrowing. Our large female boa has a climbing tree (she's in a 9 foot high enclosure). Our male boa doesn't have a climbing aparatus yet but will have one when his custom enclosure is completed sometime this summer. For now we regularily take him out so he can climb around the house (supervised of course).