Tanzania and/or Uganda safari companies

Though you mentioned you don't want a private tour, you might to just want to contact The Far Horizons (do not confuse with the American company Far Horizons which does archaeological tours) for a quote. You might be surprised that the cost can be less than on a group tour. Strange, but true as you are dealing directly with the local supplier. I have found this to be true in China, Ethiopia, Mexico, India, Senegal, Ghana, etc.
The Far Horizons
www.thefarhorizons.com
email: info@thefarhorizons.com
Arthur Kakai is the General Manager and the company has offices in Uganda and Rwanda
My guide, who was excellent, was Isaac Ngarambe

Before you say you
don't want OAT, I've been there with OAT on their "Best of Kenya and Tanzania"trip and can give you a good "heads up." First of all OAT stays in tented camps, not lodges going from mobile camps with bucket showers to a bit more "luxurious" camps with four-posted beds surrounded by mosquito netting and both indoor and outdoor showers. Second, because OAT stays in mobile camps that are in close proximity to the Mara River, you have a better than even chance of seeing the migration if you go at the best time. We did, and we saw the migration and the crossing, just like on 60 Minutes. Now, I'll offer that OAT for most of their trips does NOT give you the best value for the money, but their Africa trips are an exception. They're among the best, if not the best deals around. I won't endorse OAT in general, because many companies can offer better itineraries for other trips, but their Africa trips are an exception.

I would highly recommend a small company called Access2Tanzania (access2tanzania.com) for planning a safari to Tanzania. My friend and I wanted a private tour for 2 and it ended up being comparable in price to other larger companies' small group tours. The owners live in the US with a partner on the ground in Arusha, Tanzania. They have also recently expanded to trips to Rwanda. From our first contact with Karen, one of the owners, to the end of our tour things were pretty much seamless! We had a great guide, our own vehicle with electricity onboard for charging various devices, and a refrigerated cooler to keep lunches and water cold. In terms of wildlife sightings, the tour definitely exceeded our expectations! I would encourage you to contact A2T, tell them what you're looking for, and get a quote. I think you may be surprised! One of the strengths of the company is that they use only their own full-time guides who get a decent salary, benefits, and training--no contract guides. We also really appreciated their social mission.

Check out Shadows of Africa. We did a private tour of Kenya and Tanzania with them and were extremely happy with our trip. Get quotes before you rule out a private tour. You have many ways to control your total cost. The most obvious is the cost of your accommodations.

If you go to the top of this page and click on "Resources" the select "Tourism Offices" scroll down to Tanzania and Uganda they have links there you can explore.

I used Wild Encounter Safaris ( https://wildencountersafaris.com/destinations/tanzania )and did a week long (almost) safari covering Lake Ndutu, Serengeti, Ngorongoro, Tarangire and Arusha National Parks. I saw massive migration of wildebeest and zebras! It was such a fantastic experience!!