are you a dealer tech?
you should already get this if you are
if you are not a dealer tech then even if you do manage to get the cable it won't do you much good because the diagnozer program is only distributed to dealers and assigned to each tech's laptop via a service tag off of the laptop.
So in effect they won't sell it to you.
also a GSE handset and cable is different than using the diagnozer program and cable. The GSE handset uses the OBDII connector in the harness, the diagnozer uses the other specific cable with different connector to link to the vsm.
Just FYI ;o)