You will get lots of advice from your request for help. Here's mine:
We operate a small safari company and ALWAYS suggest that first-time travelers on safari go to Kenya. Set up an itinerary that includes
Samburu, one of the 'tree lodges' such as the Ark.. visit Lake Nakuru and
Masai Mara. Add Amboseli if you like. If you can get to Masai Mara early in October, you will see some of the great migrating herds of
Wildebeest & Zebras.
East Africa safari costs are moderate - accommodations are good to very good, though not as lush as most places in southern Africa. Having a Guide who speaks good English is virtually guaranteed, though these men are not trained in the manner of Guides (or Rangers, as they are more commonly called) in southern Africa, where training and certification are more formalized.
Well, Mala Mala is one of the most expensive places you could go, though one of their lodges is not quite so costly. Botswana, generally, is expensive all across the board.
Remember that your total cost will be the sum of your accommodations, plus transportation to get to the camps, plus park fees.
In east Africa, you will normally be paying a safari operator to provide the
vehicle and the Guide and you will drive from point to point. There may be some flying (and I think, SHOULD be some flying). The operator will bundle all the costs, add a markup, and give you a total. This might be about $500 per day per couple, if you have the vehicle & Guide to yourselves.
Here's an itinerary we operate that is a good cross-section of what Kenya has to offer:
http://www.africasafari.com/june.html
I'm not showing you this to sell it to you; we're taking time off right now and our company is "resting".. but this is a sample of the diversity that you can experience in Kenya in one trip.
In southern Africa, you have Guides and vehicles at the camps and you will typically fly to the camps. Here, your cost per day is all-inclusive, plus the cost of the flight. Some travelers will (for example) rent a car in Johannesburg and drive to the camp(s) as a way to save. It is safe and can easily be done in South Africa. Botswana is all flights... from
Johannesburg to Maun (or Victoria Falls, Zimbabwe) and then flights in small aircraft from camp to camp.
South Africa, especially, offers you opportunities to have some other valuable experiences. Lots of history here, both good and bad.
Extraordinary scenic areas of the country and Cape Town - perhaps the world's loveliest city.
So.. my thought is: Kenya (and maybe some of Tanzania) for wildlife,
South Africa for more diversity. Botswana for isolation and privacy in the small luxury camps.