Used Speedmaster. For me, also a used Navitimer. Seam as well if that is your thing when speaking about “grails”. Tudor is a possibility as well but for me personally, they make great watches but not “grails” so to speak. Highly subjective though.

Speaking of subjective, if you like watches with a bit different style, you can get almost anything from Doxa in that range and have a bit of money over.

I’d keep the Flightmaster. The rest isnt completely my style, although i also somewhat like the Seiko GMT und the Citizen Diver in the top, second frem left.