My limited experience with two-handed rods in the salt makes me lean toward faster, 'Euro-style' rods in the 12'-14' lengths. The set-up gives a considerable distance advantage over the standard 9' x 9 wt. striper/bluefish rod. I overhead cast with shooting heads--no spey casting from the beach.
I fish two-handed in the surf, but still prefer a 9' rod from a boat: distance is not a concern from a boat (boats move, beaches don't--at least not very quickly!), and I still have not figured out a good way to land a fish in a boat by myself with a two-hander.
Thomas & Thomas, located in the Bay State, makes a 12' x 12 wt. two-hander for the striper/bluefish market; it's a cannon and a superb rod. I'd rate the rod closer to a #10/11 wt., and not a true #12 wt.
Rumor has it that Massachusett's own Juro Mukai of CND rods is currently developing a two-hander for the surf. Juro guides full-time for stripers; keep an eye peeled for this new offering.