Don't think I've ever dove with aluminum 100's? I've used HP steel 100 and 120's. I reserved a larger tank from Blue Angel for our upcoming trip, I hope it's a HP tank.
It will not be an HP tank. The larger tanks they provide are AL 100's.
The ONLY operators on the island (aside from the tech guys) with STEEL HP tanks are Aldora, Liquid Blue and Living Underwater. Anyone else that has larger tanks available are AL100's and will range anywhere from $5 - $10 more per tank.
I still encourage divers to work on gas management vs. relying on larger tanks if that is the reason they like the larger tanks. With a properly profiled dive, most of my divers still get 60 - 70 minutes from an AL 80 - and if they aren't getting that at the beginning of the week, they are by the end of the week from the tips and help from myself and crew to help them improve their gas management!