I think you'll find plenty of disagreement on this issue. Personally, I'm a fan of UTH for my snakes (none of which are currently BPs) but some feel that the overhead heating is enough & mimics the way that sun warms the ground that wild snakes use to warm themselves. I don't think it matters, as long as your snake has the needed level of warmth available to him one way or another.

Wait for others that actually use RHP to chime in with actual suggestions for what you need in setting this up.