The Seva 123
is and was my pack stove of choice. The same one has been with me since '83 and it always starts. three continents, sea-level (actually below sea-level) and up to 13,500 feet, all seasons, temp down to -50.
for a long time I did not know about the "optional" pressure pump. In those cases I just poured a little bit of gas around the throat and that got it going. I've mostly burned white gas but in a pinch gas, mogas. I've been told diesel, pure alcohol and good scotch will work too.
It does have a 'jet engine sound" aspect to it when it's at operational but as said before, if you're worried about noise you should probably be worrying more about light discipline. Of course when you awake to that roar you know someone else is making coffee and you don't have too!!
Probably the thing I like the best about it is with the cover / cup replaced over the burner it can go right into a nylon mesh bag and straight into your pack stow pocket without fear of burning yourself or melting anything.
http://www.spgear.org/gear/555/svea-123.html