Hi,
I have always used a great US based "safari" travel agent. I travel the world for business and set up my own travel, but I rely on an expert for my family trips to Africa. The TA travels to SA, and Southern Africa a couple of times a year (and has been doing it for +20 years), he knows most/many camps, sites, areas and makes great reccomendations so my trip, fits the way my family likes to travel. Yes, we are adventurious, but traveling with family on a "once in a life time" trip takes some planning. FYI we are on our third "once in a lifetime" trip. I have never met this TA, he lives on the other US coast, we do everything by email, with many questions asked and answered back and forth.
I would also reccomend doing as much research on your own on line as possible, I know can be confusing, but if you have some idea about what you want to do, what you like, and what you won't do, it will make the planning easier.
Hope that helps.