Well,
First of all, congratulations with your marriage!
Commenting on the replies you've got, there is some very good advise. Altough I do not agree totaly.
I've spend my share of time in Africa, both working/living and on safari's.
I also have: the 55-300mm, the 60-250mm, the 18-250mm, the 16-50mm and several TC's.
The good advises: take a bean bag for in the car, the 16-50mm, spare batteries, dust cleaning kit (rocket blower), enough memory cards.
For tele, I've done 3 weeks Tanzania (incl Tarangire, Ngorongoro, Serengeti, and other parcs) just with 1 lens: the 18-250mm! With very, very decent results.
See some of my gallery pictures.
Our last trip, travelling through Zambia last September, I took a 16-50mm, 60-250mm, the 55-300mm and TC's and 2 bodies with me.
The best results are with the 60-250mm without TC. I used the 55-300mm for no more than 20 pictures (out of 3000).
Often wildlife is close enough (yes, it is, even when you are on foot), to need very long lenses unless you are going for birds.
Cats, elephants etc can walk or sit very close by.
If you have enough cash, I'd go for the 60-250mm and a TC. It is a very good lens, dust sealed.
Since you'll be in a safari vehicle most of the trip (I guess), size and weigth is not that much of a problem.
Otherwise the 55-300mm is a good (for its price) and cost effective solution, with a TC it is not that good in finding focus.
I'd consider a second body for mounting the 16-50mm for fast reaction time and avoiding dust by lens changes.
I'd leave the 50-150mm and the FA50 at home.
Some 18-250mm safari examples here:
Picasa-webalbums - Bert - Tanzania 1-9-...
Some 60-250mm safari examples here:
Picasa-webalbums - Bert - Kafue
Have a nice trip!
- Bert