Best lens for a gorilla trek in Rwanda?

Discussions
1

I’m an amateur, with a new Canon R8. Have the 100-400 lens, which was often too powerful on my recent trip to Tanzania, and the 24-50 mm that came with the camera. Miss being able to use my Tamron 75-300 on my old Rebel. What lens would be best for gorillas, which will hopefully be very close, plus suitable for colobus, chimps and wildlife in general. Price not a factor, weight and size is big factor, smaller the better. help!