You cannot go wrong with either!

I am a fan of the ProLine material and construction. The plastic they use is very tough and will outlast you. Does not hold heat quite as well as the 1/2 inch PVC that I think AP's are made with, but the difference in insulation is not enough to worry about.

Radiant heat panels will work well for a large cage like those. Either one larger panel or two smaller panels. Of course Flexwatt or similar heater is also a good choice. I think RHPs are just easier.

IMO a 6ft cage should be plenty of room for any boa.