In steel you have low, high and intermediate pressure tanks.
For low pressure I know 77, 80, 95, 108 and 120cf are common 77 being older tanks that are still common in use. The rest are common modern sizes low pressure are 2400 psi and with a plus "+" rating gain another 10% pressure capacity (2640 psi) which is the pressure they make their volumes at.
High pressure tanks are 3500 and some special tanks even higher. I know these to be available in 80, 100, 120 and 130 cf
All of these both LP & HP can and have been configured for Doubles. LP are commonly also used at over their rated pressures which allows a diver to stuff in extra volume for extended bottom times. This is common among cave divers that feel the need for the extra volume in a smaller tank to squeeze through tight spaces.
I does however pose a risk of tank failure and explosion. These tanks even when not exploded will be capable of far fewer fill cycles and will experience early hydro failure.