Hello, welcome to the world of diving. Glad there is another desert diver among our ranks.
I don't know anyplace in town that for sure that rents them, but I would try El Mar in Mesa, Sea to Sea in Phoenix, and then No Limits in Gilbert. They all sell more technical type gear. My LDS is Inland Water Divers in Goodyear and I highly recommend them, I just don't remember seeing a BPW on the wall anywhere. But it might be worth giving Pete a call.
Also, unfortunately most of the divers out here have gone to Faceb()K for dive conversations and I have had no one respond on the Southwestern region to a board post. So if you are a member of FB I would try two of the more popular groups: State48 or Arizona Scuba Divers, there are plenty of people that will give you plenty of input lol.
If you catch one of us BPW people at Vista Point just give us a shout, I'm sure someone would be more than happy to explain why we like ours.
Happy Diving.
Rick