I have the Cycleracks front and rear racks for my TW200. I highly recommend looking into at least the rear if you haven't already crossed paths with that company. Easy install and can accommodate quite a bit of firewood, groceries or whatever else you find yourself lugging to or from camp.
Just got a 2009 Kawasaki 250cc Super Sherpa for the back of our MB 1120 build. Was also looking for a TW200 but this one came up locally at a good price. Disc brakes front and rear, stainless exhaust and looks to be good build quality. I guess a bit rare in the US which is a bit limiting for aftermarket parts.
I have a Super Sherpa as well for the back of my RV. I'm on my second one, first was stolen.
I like it so much better than all the others mentioned here so far.
It's air cooled, has a carb, and can be worked on by just about anyone around the world.
It's fairly light at 280 pounds, has normal size tires that can be easily found.
I put a top box on mine and can go into town, get groceries, do laundry, etc.
Has rear passenger foot pegs and grab handles for 2 up riding.
I also have an extra front sprocket, one size up, for doing more highway riding.
The bike is geared pretty low stock, the 6 speed gearbox is nice.
It's damn near bulletproof, just what you need for exploring away from base.