Looking for a full-service operator: Kenya safari + Diani beach, August 2027, group of 10-11

Hi all would love your help. Planning an extended family trip and looking for recommendations for a tour operator who can handle the whole thing end to end. Would rather pay someone who knows what they're doing than piece this together myself

- 10-11 people, extended family, arriving from three places
- 2 travellers have limited mobility, they can walk short distances but tire quickly. No wheelchairs. Tho. Would appreciate a camp with flat compact grounds, short walk from tent to dining, no long boardwalks, no stairs, ground-floor rooms
- Age range 21-65

When
- August 2027, going for the Great Migration
- Around 8 nights on the ground, 10 days total including travel

What we want to do
- Masai Mara, 4ish nights, with river crossing attempts
- Hot air balloon safari (at least for those who want it)
- Giraffe Centre and probably Sheldrick in Nairobi
- A Maasai village visit , if anyone has a view on which operators do this respectfully
- Diani Beach, 3-4 nights all-inclusive, to finish

Accommodations
- Mid-range to lower-luxury, roughly 4-star equivalent
- Important: I want a camp with multiple room categories, because budgets vary a lot across the family. Some people want to upgrade their tent, others don't. Ideally everyone sleeps at the same property at different price points if possible

Budget
- $3,500-5,000 per person for land costs, excluding international flights to Nairobi
- I suspect that's realistic for the safari portion but tight once Diani is added. Happy to hear that I'm wrong, or that it means dropping a Mara night. Would rather know now

Id love to know
Who have you actually used and would use again?
Anyone dealt with a group split across three continents converging on Nairobi? Any operator good at that kind of coordination?
Anybody have experiences with mobility accessibility?

Thank you!