Will the 45# wing do ok with doubles 10l or 7l?
It depends on a lot of things. Whether your tanks are steel or aluminum, how much weight you carry, and how much air you put in a dry suit (if you have one) vs. put in the wing.
All I can tell you is that I use the 60# wing with twin 15L tanks and it works just fine... it's actually a bit too large.
Yes, we have used this wing with 10l/80ft3 doubles. It is both stable and streamlined.