Texas LTH, Having seen that you are considering a rifle other than or in addition to your 30-06, I'd like you to take a look at a 35 Whelen. Even though my sons and I took some of our animals with '0-6s, most of them were taken with 35 Whelens. The majority of African PHs would prefer a larger bullet traveling at a slower velocity than a small bullet traveling at a high velocity. That being said The Whelens use a larger diameter bullet with weights from 200 Gr to 250 Gr. Take a look a the ballistics, for a few more grains of powder you get a lot more energy. For instance my normal '0-6 load for Whitetails is 54.7 Gr. of Win 760 pushing a 180 Gr. bullet. The load I used on my Eland was 59.0 Gr of 4064 pushing a 225 Gr Barnes TSX. Nikon's Spot On Ballistic table shows The 30 Nosler w/ 200 Gr. AB at 2598 fps and 2998 ft.lbs of energy at 100 yds and 2448 fps with 2660 ft lbs of energy at 200 yds. Compare that to a 35 Whelen using 225 Gr AB at 2539 fps and 3221 ft. lbs of energy at 100 yds and 2335 fps with 2723 ft. lbs of energy at 200 yds. A little bit more energy at both distances, but with 20 plus grains less powder. My hand loaded Barnes TSX were slightly "hotter" than the Nosler Factory loads but you get the picture.
I left my 375 H&H and a 416 Rigby sitting home in the safe while the 35 Whelen went to Africa.