My suggestion would be Marlin's 338MXLR, 338MX or 308MXLR or 308MX. They seem to fit your needs of a deer and hog rifle along with Africa hunting needs.
These fine Marlin lever action rifles give you the power, especially in the 338 Marlin Express, that your hunts need(leopard) but are not excessive for deer. Plus they are true 300 yard rifles especially in the longer (24in barrel) MXLR versions.
I personally like the look of the MX versions of the Marlin with the walnut wood vs the laminated wood on the MXLR. But the Marlin 338MXLR seems to fit your needs and wants. Wood, stainless, power, pistol grip, scope friendly, and American-Made.
The 45-70 and 450 Marlin cartridges are wonderful and very powerful but fall short on distance shots past 200 yards so why not go with something that really doesn't limit you to shorter distance shots. Most of us probably shouldn't past 300yards anyway.
Form certainly does matter and I fully agree that a deer rifle should be more than just function.
Good Luck on your new rifle hunt!!