IN 2003 Luxfer introduced the Luxfer Limited 4350 PSI HoopWrapped Aluminum Cylinder. These things were / are great. They come in 2 sizes. 106 cuft and 85 cuft. The 106 is the same physical size as an aluminum 80 and the 85 is the same physical size as the alum 63.
I had/have the first batch that came out of the factory and was doing the water tests on them. They were/are outstanding tanks. The bouyancy of them is great and they are nicely balanced. Only one thing ...... if you want the rated volume you gotta have the 4350 psi pressure. If you can only fill them to 3000 psi then you have effectively an 80 and a 63.
The price on these retail is in the $325 range which put them in line with HP steel. The only problem from a marketing standpoint is that there are few dive centers set up to fill them. As a result they were a dud. At best I belive they sold a few hundred. But they are still available on a custom order basis.
These are a standard thick aluminum with what i like to call the "kevlar girdle" to help with the greater pressure.
Carbon Fiber wrap cylinders were used early in tech diving as experiements. These are very light and hold a lot of gas at 4500 psi but float like a cork --which makes them unattractive for diving.
The big market for carbon fiber wrap cylinders is the home-health care market for granny to tote her oxygen bottle around and not feel like she is lugging a bowling ball.
Paintballers also love them for weight and agility.
Hope that helps you.
Regards,