John,
I am biased, but I would choose a classic "British" look if it were my project.
Typical short forend with horn forend tip, 26" barrel, enough weight to allow reasonably comfortable shooting with 650grain "Light Nitro" if that were needed. The .577 75 Cordite 650 grain bullet loading does recoil rather convincingly in a light rifle.......

You would certainly have a proper "thumper" stalking rifle. A double .577 2 3/4 Express would be so very "pukka", but there is something about a nice slim single shot stalking rifle in the hands.

This is my Tranter Double Patent .500/.450 #1 Express with 28" barrel from Cogswell & Harrison, circa early 1870's. Of course a .577 would have a more robust looking barrel.
- Mike