Yukon Ultra Stoves

Hi all. In Feb I'm competing in the Yukon 100 miler where temperatures may drop to a chilly minus 40. As part of our mandatory kit is a stove to boil water. I want something small and was looking at the Trangias with a Spirit burner, which they say will work in colder environment even below minus ten, but up to minus forty? Any other solutions greatly appreciated

http://www.likeys.com/

I dont know much about stoves or the Yukon, but speak to Martin at the above website and I am sure he will advise you

+1 for Likeys

Martin organises the Arctic 6633 Ultra so knows a bit about cold weather events

+ 2 for likeys!

I'd highly recommend the primus omnifuel stove. This is what gets used on trips to the North Pole etc. I've used them at minus 40ish with no problems. Can run on any fuel. MSR whisperlite comes a close second. Usually a bit cheaper too. The heat is easier to control on omnifuel - you could use it to simmer, but often that isnt a consideration as usually in those conditions you're melting snow ASAP to boil water for rehydrated meals/drinks etc.

Used an msr whisperlite when I did the iditasport 130. Worked fine. Never reached -40C, but I've been told they still work ok. Coleman fuel  also have the advantage that it's easy to find in the states and if you need to start a fire real fast (say if you've broken through the ice) then it will get wood burning quick. 
Size and weight need to be secondary concerns compared to being able to produce heat when you need it.