This winter I found an old KHS mountain bike to convert to an expedition machine. I stripped it down to bare metal and installed two more sets of bottle cage mounts (it only had one) and brazed on a decent rack mount on the front fork dropouts.
Next I prepped, primed and painted it bright red so I'm more visible in traffic.

I set it up with mountain bike running gear that I already had but took the advice of this forum on some things such as the Brooks B-17, the Road Morph pump and then decided on a Trekking handlebar. The tires are Conti Country Ride 1.75s.
I've got about 65 miles on it so far and love it, it's the only bike I have that I feel comfortable (I'm a decrepit senior type) riding with no hands.
Next things on my list are a proper seat post (using the old steel one now) and to build up a set of 36H wheels.
My only gripe so far is that when out of the saddle pedaling, I occasionally touch a shifter with my knee (SRAM X7). No big thing. When I'm loaded and traveling I find I rarely get up out of the saddle anyway, preferring to trudge along in low gears.
Bruce