so you shouldn't have any problems with setting the GMT hand. It's as easy as the Rolex GMT models.
Just the main thing which will give you a hair pulling is all the various GMT models. Furthermore, the new P.900X and P.200X models have the GMT function along with the "GMT" designated models such as the PAM88, 159, etc.
So I'd first narrow down the choices by picking a Luminor or a Radiomir.
If a Luminor, then narrow it down more by picking a Luminor or a Luminor 1950.
And then from there, it should be a little easier to narrow down the remaining choices.
Cheers,
Anthony