i would say hardtail,
i did a 5 week tour in scandinavia on my hardtail,
which i changed the tyres to continental travel contacts (v good tyres)
and put barends and a pannier rack,
that’s it, oh and an extra bottle cage,
the gearing seemed suitable because of the weight you have to carry,
and the frame and parts are up to it as it is designed to take a bashing off road,
even having front suspension wasnt an issue as the rear is so heavy the front mainly glides over stuff,
my r7’s did have an auto lockout platform damper thingee though
you dont ride out of the saddle much with a full load,
and your thankful when you do hit something
only problem is lack of front mounts,
and the rear triangle is shorter so unless you put panniers right onto the rear of the pannier rack your heels might rub/foul the bags,
again wasnt a problem for me
hardtail is a jack off all trades in my eyes,
just get the riding position right whatever bike he buys,
but you kinda only find this out from riding the bike for a long period of time to be honest.