Read the hunt reports and you will get a great feel for what is on offer.
I think this is some great advice. I've seen so many first timers with Africaitis and they just know they want to go to Africa but don't really understand how diverse Africa is and what a wide variety of terrain and species are available. The shotgun approach to finding an outfitter just doesn't work. You really need to define some parameters. At least answer this list:
1) Do you want to hunt free range or are you okay hunting behind high fence? (No right or wrong answer here, just personal preference. If high fence is there a minimum size?)
2) What type of accommodations do you want? (Even most tent camps in South Africa are luxury but do you want tent, chalet, 5-star?)
3) What are your primary target species? (This matters a lot because not all areas have all species and some areas are better than others for some. Obviously your list will grow and change once in country but it's good to pick out two or three of the ones you want the most)
4) What style of hunting do you want to do? (Do you want to walk, drive and stalk, use archery gear?)
5) Do you want to hunt one property exclusively or are you okay driving around to different properties?
6) Does there need to be things for your spouse to do?
7) Are you taking your own rifles?
8) Do you want to hunt birds or fish as well?
I'm sure many here can add to this list. As you said this is a big investment and to get the most for your dollar and the most to fulfill your dream of Africa, you need to know what that dream is. We've hunted six different camps in South Africa and Namibia. We've stayed in 5-star lodges and we've camped in pup tents on the desert. We've hunted high fence and we've hunted free range. But, we defined our goals on each and every trip before even talking to outfitters. That way we began with a short list. On our most recent trip to South Africa, we started in a 5-star lodge because we were going with several other couples and several of the women weren't hunters and wanted gourmet dining, fine wine and a pool. From there Vanessa and I headed to a small operation where we were up well before daylight each day and going to bed often very late after hunting hard all day. We both agreed it would not have been a good choice for the couples portion of the trip as there was little time for socializing and relaxing but it was perfect for the two of us looking to hunt hard for some very unique species. You have a great resource here in all the hunt reports and reading through them will help you establish your goals and desires. One can just not simply go to Africa. What you think you know about Africa right now is about 10% of what you'll know after your first trip and about .1% what you'll know after your 10th trip. You've come to the right place for some good advice. The best rated outfitter in South Africa will ultimately be the one you choose because they fit your criteria. Just because I think they are great doesn't mean they are right for you.