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Most Windows-style keyboards will work on a Mac (I am typing this on a Ducky Shine connected to a Mac mini). F9 to F12 do Expose etc.
There is no eject key, however I am running an app that puts an eject button in the menu bar, and besides, I don't use the optical drive much anyway.
Oh and F1 to F7, when pressed in conjunction with the extra "Fn" key, do volume control, play pause etc.
Plus there is a switch under the keyboard that swaps the left Alt and Windows keys to match the Mac's Command and Option layout.
So pretty any Scandinavian layout mechanical keyboard should work, just that the key legends won't exactly match a Mac keyboard, but you should be able to get custom key caps for that.
When looking, I found that there are very, very few Mac layout mechanical keyboards at all.