question backplate doubles

Hi, I was considering getting into diving doubles, and I was wondering what type of wing I should get lift-wise? I would be diving a set of HP Steel 80s, with a 7mm wetsuit. If more information is needed just ask away, I just want to figure out what I need.

I got this backplate with a pair of 19cf ponies. There was a custom made twin holder on the back. It's a stainless 3mm backplate but there are no manufacture info anywhere on it. Hopefully I got the picture attached.. it looks like a basic backplate - single strap slots and standard 11" bolt...