Hi Daniel,
Depends which camera system you are using? Nikon iTTL uses 5 pins as in Nik V, Ikelite. Canon ETTL uses 6 pins as in S6. You may also need a TTL converter either Sea & Sea's own or a 3rd party like the Hienrich. Check your flash manual/S&S website to see if it will do TTL with your camera?
If you "only" want manual flash then only 2 pins are needed so any of the connectors should work.
Some manufacturers while fitting the right sockets only wire their hot shoe plugs with 2 pins, in which case you would need to go back to your dealer! I think Subal give you the option by moving the plug connection on the circuit board inside the housing.
I have seen a Subal for Canon with 3 pin Nikonos sockets, so again would need to go back to dealer.
While TTL is nice to have, it doesn't work in all situations. Static subjects are fine but skitish ones will start to move as soon as the preflash is fired (which the camera needs to assess the output) and the milliseconds between is enough to miss the decisive moment
Hope this helps?
Cheers
Pete