I would be more inclined to think that a Centerfeed would be a better choice than a Staggerfeed, but I am more partial to centerfeed as I have had better luck with them overall for normal stuff. I have CF and SF actions available for me to try so I am covered either way. That being said, and thinking a bit more on it, it strikes me (upcoming pun intended :P) that if I were to try and do a 444 or 460, it would be on a Striker, and that would require me to use a SF magazine.

I have minimal experience with the Mauser actions so I cannot say. A CRF may be a great idea. Me, when I get ready to do it, I am going to use a Striker and make the barrel maybe 18" so that way if it doesn't work, I can set it back a bit and rechamber to something else if needed.