The "polar" is the one I would get, some would argue it's Rolex's last true tool watch. It'll easily be worth 5x current retail price in a few decades. It sounds like you're collectors yourselves! When it comes to Swiss brands I've only ever owned Rolex and Tudor. Although Grand Seiko makes a wonderful watch and are technically superior to many of the Swiss brands, for me, they're just inconsistent when it comes to nailing some of the details (i.e., the dials are incredible but bracelets aren't always up to par). GS also falls short from an investment perspective, they make too many (and too many models) for them to be scarce.

I've always had a soft spot for A. Lange & Soehne