There's a lot to be said for going with a complete bike like the Safari. If you were to go with a vintage mtb, you'd want to find one from the 80s as those tended to be longer wheelbase bikes. By the 90s, they became better offroad racing bikes as the chainstays became shorter. The shorter chainstays make them somewhat less useful for touring. I have an 89 stumpjumper comp; it has great geometry for touring with a 41 inch wheelbase and lots of clearance for fat tires, rack, fenders, etc. I have a 91 team stumpjumper; great bike but the geometry is not so great for touring.