Welcome to TRF, JS. Don't worry about the language or spelling. We have quite a few members who are similarly challanged - examples include Daren, JJ, Frans, why the list can go on and on and on . . . .
My vote would be for the all black GMT (but if you've been reading this forum, you know that I am terribly biased
). But really you can't go wrong with either the GMT or the Sub date. Both are great watches that will last several lifetimes.
John's right. Go across the border (leaving any current watch at home) and buy in the U.S. Then wear it back across.