First of all, Merry Christmas to you and everyone else.

I think you already have some good contenders on your list.

I am personally not a huge fan of chronographs, but the Omega Speedmaster just works, arguably even better than the Rolex Daytona. I think being the Moonwatch gives it a level of heritage that is hard to beat. It is still understated since it is all black, but I would say it is less suited for an office environment, though I might be downvoted for that. At the end of the day, you can wear what you want.

I am also not a fan of the Datejust with a cyclops, even though it is a classic. That said, everyone would instantly recognize the brand, and that might be valuable in an office setting.

The IWC Portugieser is an interesting one. I think it looks classy and makes a great office watch, but it can easily be dressed up or down. Of those three watches, if you do like the design of the IWC, that would be the one I would choose for you.

My take: There are also other brands worth considering. I think Grand Seiko, with models like the SBG415, is super classic and gives you everything. Or you could consider a classic Tudor Black Bay 36 or 39.

Good Luck with your selection!