fp Mirrorless

I shoot on Sigma FP L, pretty much the smallest full frame cinema camera existing, the autofocus on that thing is non existent, but it has electronic contacts for modern lenses, unlike this GoPro, I just don't know how your friend is going to use this thing.

the a7cr is the direct higher end version of the a7cii, buy for most people the sensor is probably overkill and the rest is the same. so for you a7cii might just be the best option. the canon r8 is cheaper, slightly lighter and arguably more ergonomic, they are pretty similar but the a7cii has ibis

The absolute smallest would be the Sigma fp and an adapter. Everything would be manual though, and it's ridiculously unergonomic for this kind of use.

Really rough to find small lenses for L mount, best bet is probably Sigma's 'i' series, or adapted rangefinder glass (SLR glass the adapter is going to be large). Check out r/sigmafp for vintage glass ideas. There is also of course the manual focus fixed f/8 26mm Lumix

I would go with the Sony A7c; it's not as "film-camera-like" as Fuji but it's very small and full-frame, and almost every kind of lens can be adapted to it. I used Minolta lenses on my Sony cameras for years. The Fuji cameras are APS-C, which means your lenses will have a narrower angle of view. The