I did 6 months in Africa just over 20 years ago now, agree - don't try and pack too much in. I did East Africa (Kenya, Tanzania (including Zanzibar), Rwanda, the then Zaire, back to Kenya, Malawi, Zimbabwe, Zambia, Botswana and SA. That took 3 1/2, nearly 4 months. You need to allow plenty of time, things don't always move that fast with transportation but then thats part of the char.

While in some places LP has become a joke, I think in Africa is still pretty good. Absolutely read the sections on vaccinations and visas in depth but some things you just can't plan for, we did find we had to change our plans sometimes. Tripadvisor is a pretty good resource too, alongs with the Lonely Planet blogs.

Good luck. You'll love your time, it's still the one trip in my life that stands out and I've had a few now (and some much more luxurious too but this is the one I remember most fondly).