Hi,
If a shoulder bag works then I can recommend ThinkTank Mirrorless Mover 30i. I got it recently and I am able to fit
- R6 + RF 24-105L (laid on its side, grip side up ready to go)
- EF 70-200 f/4 L + hood inverse fitted (RF 100-400 will also fit with the hood inverted, I tried my friend's RF 100-400 and fit much better in that bag)
- Also, I actually place the little EL-100 flash and EF-RF adapter at the bottom, attach one of the separators which came with the bag on top of that and then place the R6 + RF 24-105 on top of that.
- And after all that there is space for RF 50 1.8 (or 16 2.8), and and a couple of extra batteries.
The only slight issue is that the additional RF 50 or RF 16 will have to go on top of the camera body and will get in the way while taking the camera out and putting it back in and could be an annoyance if you plan on doing that frequently.
You could in theory try placing the RF 50 at the bottom and then use a separator on top of it and place the camera on top but not sure if that is a good idea with the STM Lenses ?
I am planning on getting a JJC lens pouch for the RF 50 and attaching it outside the bag if I do end up carrying the RF 50 just in case.
HTH
--C