A backplate and wing can handle both single tank and doubles. The only difference is you need a separate wing for singles and doubles.
Most people use either steel or aluminum plates. Some doubles divers use aluminum if they would be overweighted with a steel plate.
You’re going to want HP (high pressure) tanks. Unless you’re in FL cave country or have the odd shop elsewhere that doesn’t care, getting LP tanks filled above service pressure is a freaking PITA. I drive an hour each way to get my LP85s filled to 3000 when I’m cave diving (mine) in WI. Service pressure is 2640 on my 85s. But they are so nice to dive.
Get the HP100s. If you ever decide to sell them, they go quickly.
Most people use either steel or aluminum plates. Some doubles divers use aluminum if they would be overweighted with a steel plate.
You’re going to want HP (high pressure) tanks. Unless you’re in FL cave country or have the odd shop elsewhere that doesn’t care, getting LP tanks filled above service pressure is a freaking PITA. I drive an hour each way to get my LP85s filled to 3000 when I’m cave diving (mine) in WI. Service pressure is 2640 on my 85s. But they are so nice to dive.
Get the HP100s. If you ever decide to sell them, they go quickly.