Yeah keep checking BBTS, I saw the Night Ops Steel Brigade and Killswitch pop up for availability yesterday and the original Swarm Trooper is available again right now, you never know.
I know Atlas is a heavy machine gunner, and there are desert and arctic themed troopers coming. He has mentioned doing airborne and divers, but nothing else is known. I think we will see more unveiled at Joefest at the end of June.
As for the Gridiron diver set; from what I've heard, take caution with the straps of the flippers and dive mask, they can break if you stretch them too far. I recommend picking out feet that will fit before trying them on.
BTW, GI Joe Classified is coming out with a Torpedo figure, you might just want to wait for that one.
A couple of reviews of the Gridiron set:
Laruan ni Obiwan part 1
Laruan ni Obiwan part 2