This operator can help select your international flights, but you'll have to book them yourself help
Fly to/from Abeid Amani Karume Airport (ZNZ - Check price) on Zanzibar. Or fly to/from Dar es Salaam (DAR - Check price) . There are daily ferries between Dar es Salaam and Zanzibar.
A transfer from and back to the airport can be arranged for an extra cost
Additional accommodation before and at the end of the tour can be arranged for an extra cost
I just came back from a 3-day safari through the Serengeti National Park and Ngorongoro Crater, and it was an unforgettable experience. Not only did we get to see the famous Big 5, but we also encountered zebras, cheetahs, giraffes, hippos,...