Wood-burning stove, denatured alcohol stove or a Solid-fuel tablet stove?

Yes Alessandra, I received it and have replied. :-)

"I'll defer the "how does alcohol perform above 10k'"to someone else."

I've used my Starlyte at ~11,500' with no problems, and I don't doubt it would work at much higher elevations. In cold weather, as Ian said, put it in a pocket to warm the alcohol up or, if using a regular alcohol stove, put your fuel bottle in a pocket before filling the stove. In my case, I just bring it into my sleeping bag for a while before making coffee in the morning.

So which kind of alcohol did you guys say I need?

"Using an alcohol stove for two hungry people was not successful in the past, and we wanted to use our perfectly sized Evernew 1.3 liter titanium pot."

These 2 guys ruled out alcohol for Latin America… :-?
http://www.backpackinglight.com/cgi-bin/backpackinglight/global_test_gear_list_part_1.html#.U31PyXJ5OSo

Isopropyl Alcohol aka rubbing alcohol. You can find this in just about any pharmacy. There are only a few stoves which can burn this efficiently so you pot won't be covered in soot, it appears that Dan's is one of them. I've never tried rubbing alcohol in my Starlyte so I can't say.

Let's get a few things straight (my 2 cents and understanding)

Esbit is probably the most versatile fuel in terms of dynamic range (temperature and altitude). It tends to be slower, it is definitely expensive and is not readily available worldwide (not just Esbit but all solid fuels). In the US, you can only ship Esbit via ground transportation. You can simmer with Esbit.

Alcohol will work down to -45 F, they use it as the stove of choice on the Iditarod races. I have used it up to 14,000 feet and saw no limitations. Denatured alcohol in the US is usually a blend of methanol & ethanol. WW it can be very different. You can simmer with an alcohol stove.

Isopropyl (rubbing ) alcohol is readily available. That being said, I find that isopropyl alcohol to be slower than DA and below ~40F can be difficult to light. I do not know about Dan's iso stove, but my design starts to loose performance above ~8,000'. You can simmer with an isopropyl stove.

Wood, as others have said, may not be available about the treeline.

Your best option to your original question is buy a Trail Designs Ti-Tri system. I would recommend the 1.3 liter as you plan to cook real food over the next 18 months. TD also has a simmer ring for the 10-12 that works great. That being said, no system is perfect and the weakness to this choice are: wood availability above tree line, not being able to find solid fuels and the limitations of finding DA worldwide. That is my option on your original post.

Now, that being said, if it were me taking and 18 month long trip in South America, I would get a multi-fuel liquid stove and carry a large fuel bottle and fill up where I could. That's the American version.

The other thing to think about is what do people down there do? You may find that the locals have an efficient way of cooking food that you haven't thought about. Consider doing what the locals do.

My 2 cents

For the uninitiated, and with all the suggestions for the popular Trail Designs Ti-Tri, it should be noted that this is a pot-specific system. Generally speaking, the whole thing will only work with the pot in which it was designed for. Just some food for thought.

Thanks for adding to this thread Jon! I've played with rubbing alcohol some with my stoves but most of that was at 400'. Nice to know its limitations.