Were I building from scratch with no shortcuts it would be a 7x57 with a 375 ruger on a ZG47 coming a close second.
Specs on the proposed 7x57?
Were I to go that way I would do a Brno 21 in something along the lines of below.
Note that the two pictures are NOT mine, they are from another forum and I saved them for personal reference...I like the stock shape.