Demas/Chapius double in 375 flanged with a stock made to your measures. 350 or 300 grain Woodleigh fmj for elephants (you will hunting as client, backed up by PH therefore no need for a big gun) 375 flanged is far "better" choice for bears, moose, wild boars, leopard and large plainsgame. H&N makes a nice cast copperwashed bullets for practise. Ordering a gun with two sets of barrels? 375 flanged and 7x65R?

Option no2. Prowl the used market and see what you can find.

Where the actions and barrels for Peters doubles manufactured? Considering the small qty etc. resale value may not be fantastic.

Cheers