This is good reading so far:
Body: the 5D will produce better images with a greater emphasis on in/out of focus seperation than a crop sensor. (You will just need an appropriate lens for the distance)
Take a spare body, preferably a film body like the 3000V or whatever is around, and about 6 rolls of Kodak 100VS or E200 slide film (trust me on this)
For Botswana do not leave behind the 17-40. Leave the 24-105, take a 50mm prime (even 1.8 is more than acceptable) and the 100-400 or a 300f4is as well a sa 1.4X teleconverter.
If I could have only one lens, it would be the 300 f4is. Everything you photograph could be around the 300 mark, but in addition:
You will be photographing lions at close quaters, where you would use anything from 17 - 100mm.
Elephants will be around the 50mm or 200-400 mark,
Buffalo will be fleeing into bushes, to a distance where a 200mm will give you a full body shot.
Impala will require a 100mm - 150mm for full body, but you must be ready to shoot as the vehicle is stopping. then they will require a 300.
Good luck with those Klipspringer where youre going!
Landscape and scenery will benefit from the 17mm end, particularly when you look at the sky, you can get a foreground interest as well asmid scene and terrific sky.
For interiors of the amazing tents, and plane and lodges, you need a 17mm lens.
For insects and stuff, take along a 12 or 13mm extension tube to convert any lens into Macro (100-400)
As for tripod and mono pod: take one not both. I would choose a mono pod with a manfrotto G clamp and a ball head with QRP. As wella s a bungee chord to strap it to the roofrack, making it more stable
Also take a bean bag, those from the POD are great and come with a screw thread, leave the beans at home and fill in botswana with coffee beans, smells fresh all day.
Make sure you take a flash! daylight nightlight all the time.
For what its worth, I do run safaris into Kenya, and South Africa so have a good idea of what you want to be are dealing with, and my coments are based on experience with your (budget) and weight limitations in mind.
On the 100-400 lens, it is a magnificent vacuum, be aware that in dusty conditions it will draw in dust and spew it all over your mirror when you zoom in (push away), and if you zoom out (pull towards you), it will jetison (filtered) dusty air into your eye through the eye peice.
Put the 100-400 lens on inside your tent in the morning and dont take it off until your car has stopped and the dust has caught up and then settled down. Zoom as little as possible, but dont make a conscious effort, just minimise playing around.
Before removing the lens wipe the lens:camera area with a damp cloth to detract as much dust a possible.
I personally would prefer to buy a prime lens, because they will last longer, than a zoom in the long term. However there are exceptions: the 70-200f4 is great even with a 1.4X and the 70-300DOis for a lightweight walkies lens, its magic
As for your worries about price, I can only offer the coment that if you take the wrong equipment it will cost alot more to go out there again, so get it right first time (and take a film backup)
So list is:
5d
3000v
6 rolls of slide film
100-400
1.4x
17-40
50 1.8
12/13mm extension tube
550Ex flash
Monopod with QRP ball head
Manfrotto G clamp with brass 3/4-1/4 thread adapter
Bean bag (empty)
about 7kg's