So many options to build a bag, this would be my generic natural light portrait shoot bag. I bring an old roller suitcase for my tripod, flash gear and other accessories if I need artifical light.
Digital
Fujifilm X-T1
Fujifilm X100T
Fujinon 16/1.4
Fujinon 56/1.2 APD
Film
Hasselblad 503CW
Mamiya 6
Zeiss 120/4
Mamiya 75/3.5
Spare film and a spare back for the Hasselblad. Spare batteries and memory cards, a lens pen, a microfiber cloth, a lightmeter.