The basis for me, too would be a two-gun battery.

Light/medium 7x57
Heavy 9,3x62

If we're looking for big game only, then 9,3x62, 9,3x64, .404 Jeff or .416 - make mine a tad modern, i.e. Rem Mag.
Out of these I'd lean towards the 9,3x64 or .404 Jeff.

For a plains game trip only, I think a 7x57 would suffice. Perhaps even something as small and light as a 6,5x55 but I doubt if I'd really go that small.

If I were after bigger plains game only, I doubt if I would put my trust into something as small as a 7mm. Then we'd be talking calibers between .30-06 and the 9,3x62.
This is the area where I have been toying most with ideas myself. Perhaps the most ideally suited would be the .338-06 or a similar like the 8,5x63 Reb. That said, I have shot Eland @ 176yds w/ a .30-06 very satisfyingly, indeed, thank you very much.
Given my recoil shyness any caliber above .30 should be quite slow giving a milder recoil than the .30-06 does (thus the "basic" choice of 7x57).
A 8x57 would be fine, indeed: load with 200grs AccuBonds and you have a sure killer. Somehow I don't see the 8mm very much as African, though. Thus the more Bellian 7mm!

Or to go super-classic: .318 WR. That would have to be paired with a .425 WR as the heavy, no?

Much as I love the lever guns I think I'd have to settle for a bolt gun, anyway.
Take-down, please.

Scope-wise someting with low magnification and a wide field of view - the new Swarovski Z6 EE (Extended Eye relief) models would fit the bill; although I could make do with a more classic model Zeiss or Schmidt & Bender equally well.
QD mounts and decent open sights.
I'm not comfortable with the V notch and bead so I wish to have a traditional rear sight with the U notch and post front sight. A modern see-through (Recknagel) would be fine, too.
Alas, my latest experience in Namibia has convinced me against red dot sights for PG. Should be OK for DG especially in thick stuff.
I'm prepared to revise this opinion if I get to use a red dot sight whose dot is smaller than 3.5MOA. Zeiss?

If a favorite lever gun could be specified - and of course one can! - I'd take a Winchester model 1895 in 7,62x53R!
So far I have not come up with a lever that could be used against DG. Perhaps a Marlin .45-70 but let's leave the lever for the PG for the time being.

Speaking doubles the heavy is easy: .450/.400 Jeffery.
The medium requires more thought. I might end up with the 7x65R. 7x57R would be equally satisfying.
If one wants to be exotic then one chooses the 9,3x65R Brenneke.

- Lars/Finland