I am traveling to southern Italy in the beginning of next month where I will be hiking at about 1500-2000 meters altitude. I expect sunshine, but who knows really(?). So my question is what film to bring. I will use a Fuji GA645i medium format compact. Largest aperture is 4 and fastest shutter speed is merely 1/400s. I will shoot nature, people, mostly outdoors, mainly B/W.

I am mostly concerned about the rather slow shutter speeds the camera is capable of and thus I might have to use a slow film. But bringing too much slow film is risky, as it may be under exposed too easily. Faster film like e.g 400 requires faster speeds which I don't have. An ND filter might be able to help me out, but this is all about experience and I lack that. I have loads of PAN F, some FP4 and a few HP5+ in the fridge.

Does anyone have any good advice?