If I had the 300 2.8 IS II and a 1.4XIII I would put the 1.4 permanently for the safari. It would be an excellent 420 4L IS. This and the 70-200 would be enough. Plus the 300 2.8 + 1.4 combination would be lighter than the 200-400. Just my opinion. However, keep in mind that I did not and I will not have experience with a safari so take all this with a grain of salt.