We ran into a few groups who had done gorilla treks - most did Uganda instead of Rwanda as it is much cheaper, maybe half as much. I enjoyed Amboseli as well, and recommended it to friends when they asked specifically about elephants and giraffes. It was a very easy park to drive around and I think were we to go back we'd do it on our own (now that we've been once we'd probably be OK keeping it more simple - this one definitely earned the moniker safari).
Since this was our first trip we booked it all through
https://www.go2africa.com/. We chose not to go with one lodge package/group. It was more expensive this way, we but greatly preferred our own driver in a 4x4 versus shared vehicles and getting to hand pick each lodge was nice too. The couple times we had to use shared vehicles at private conservancies was a different experience as you need to decide as a group what to focus on. We skipped a sundowner once as they really wanted to try to find a young elephant when we'd already seen dozens at that point elsewhere (they were really nice and on their honeymoon, so we didn't really mind all that much).
Our lodges were:
Kipalo Hills - Tsavo
Satao Elerai Camp - Amboseli
Fairmont Kenya Safari Club - Ol Pejeta
Larsen's Camp - Samburu
Ol Seki Hemmingways Mara Camp - Maasai Mara (this was our favorite)
Ubuntu Migration Camp - Serengeti
Kitela Lodge - Ngorongoro Crater
Kichuugu Camp - Tarangire (least favorite)
Victoria Falls Hotel - Victoria Falls/Chobe
Victoria & Alfred Hotel - Cape Town
When we got home I checked rates online versus what we paid and the operator added a pretty nominal fee for all the work she did. We had a couple of instances where I was very grateful to not be in charge... at one airstrip our plane did not show up for 45 minutes. Had we been alone on the field in the sun we would have probably started to panic, but our driver always waited with us until the plane came and if it hadn't shown up, our TA would have figured out what to do. Our first hotel had also accidentally booked us for September and not August so that was another call to the TA - for them, not us - and they worked it out amongst themselves while we finished our welcome drink. I was glad to not be arguing with them at midnight!