I see what you thinking, if the op doesn’t reload, you’re probably right, a 300 win mag or even a 300 PRC would offer more choices in factory ammo. Looks like the op is in Nee Zealand, I’m not sure what the ammo availability looks like there, but Federal and Hornady load ammo for the WSM with 200 grain bullets here.
It does say he wants this to be a 20” hunting rifle out to 600 yards and it looks like he is looking at production guns; I’m not sure if anyone has a 20” option for any of the discussed rounds though.
If he loads his own, builds off a custom action, or buys a production gun like a Tikka that allows a longer OAL, then a 20” 300 WSM would fit his needs very nicely without the increased muzzle blast from a win mag or PRC. I’m sure a 20” WSM is bad enough muzzle blast wise; perfect set up for a suppressor.
