As everyone will have his favourite and defend it...
So, I will just give you my opinion, here.
I value a lot the NSA, because of its historical connotation:
it is an Alarm, a Diving watch, such as the Deep Sea Alarm and the Polaris.
So, I would confess a certain weakness for this one.
BUT the Diving GMT is not a bad choice, less expensive, with a friendly complication, it is certainly not a second choice, and a nice one, too.
Same for the Chronos...Aesthetically speaking, I slightly prefer the Navy SEALs...
Trying them in real conditions will help you in your final decision, I think.
Keep us updated, please!
Best,
Nicolas