I have in my collection a full range of rifles and cartridges which would meet and/or exceed the OPs criteria........358 Win Mod 7 Rem, two 350 RM Mod 7 Rems, 35 Whelen Mod 700, 9.3X62 CZ 550 FS, three 375 H&Hs, 38-72, 405 WinX2, 40-72, 40-82, 45-70, 45-90, 45-110...........and I still would recommend the 375 H&H to complement his 270 and 243. A 375 can be as light or as heavy as one wishes and the recoil level will be determined by how the op loads for it. If he loads a 270 gn at 2500 fps he will experience exactly the same recoil as a 9.3X62. If he loads a 250 at 2600 he will experience exactly the same recoil as a 35 Whelen, if he loads a 250 at 2300 he will experience the same recoil as a 358 Win, and on, and on, and on........However if he loads a 270 at 2800 he can achieve something no other cartridge in this class can..........375 H&H ballistics......
The 375 can be had on the same actions as the 9.3, 35 Whelen etc so the rifle needn't be any bigger or heavier than any of these rifles. Hell Sako used to make it in a little 20" barreled full stock, one of the sweetest 375s I ever shot or handled and given that the OP isn't looking for fire breathing ballistics, it would fit his criteria perfectly........(except for the price of course). Then again if he purchased one of these little beauties he could use it for 10 or 20 years and sell it at a profit as these quality rifles NEVER go down in price and in particular the ones in 375 H&H. I would predict that in 10 or 20 years he could double his money if he was relatively careful and took good care of it.
Due to the mercenary ploy by Photobucket, I don't have any photos to post of game I have taken with the 375 H&H but it numbers in the dozens........from duiker to eland to giraffe to hippos as well as lion, leopard, croc and bears.
These threads got me all worked up.........I think I'll go load something, maybe some 358 Win.........or wait, I think I have 50 X 350 RM prepped and ready to load.