Buy what makes sense now, such as a .338 can, and get the large bore if and when it is needed.
Get the Vers 375, Harvester 338, etc.
Down the road, grab a Vers 458, Vers 475, ...whatever it is that fits your needs.
I'd love to give a glowing review of my Vers 475 right now. But I haven't shot it yet!
I think it's been here for a month.