I will bring a Steripen in case I need to treat water.
I sure have liked mine in field practice. I use Eneloops to power it and charge them from my SON dyno/Cycle2Charge.
For the butane I was going to buy...
For the Eastern Europe part of my tour, I carried an alcohol stove as a backup to my preferred iso-butane, figuring I could power it with homebrew rakia (moonshine) found in "secret stores" along the way. Alcohol content can hit 80% in a strong homebrew. Didn't need to use it, as I found tall and short iso-butane cartridges in a Veliko Tarnovo BG hiking store that more than lasted my four-months on the road. Alky stoves can be near weightless and are small to toss in the corner of pannier, HB bag, or rear jersey pocket.
I primarily carry a self-made "penny-stove" made from a Heineken can. With all accessories (stove, penny, pot/cup with handle, lid, stand, windscreen, lighter, SA knife, P-38 can opener, pot lifter, 2 folding sporks, fuel bottle, carry sack), it weighs 460g, about 16oz. I considered it cheap insurance and have used it as my only stove/cook kit for fast, long (300k-400k) day rides and overnighters.
Best of luck and all good wishes, George, and what sounds like a wonderful tour!
Best, Dan.