Lightweight stove - what is the lowest temperature that one can get the mini butane stoves to work at? Can you get a hanging version or perhaps rig one up (Snowpeak)?
Sleeping bag - need to get a new bag (Marmot?), go for down, DryLoft outer with 0degF rating? Which is the one that Simon got?
Snow shoes - something like the cheap MSR ones. Are there any lighter options?
Food - take much, much less. Certainly no more than one oatmeal per day, plenty of red zinger, plenty of coca tea, small amounts of suasage and other meat.
Camera - must take lighter camera for asault. 35RC or perhaps some automatic model like Martin's. Must overexpose by one or TWO full stops when looking just at snow and sky. Must have a UV filter.
Lighting - need to get Li batteries for light. Can one get a reasonable white-LED insert for the Princeton Tec solo?
Clothing - Patagonia mid-weight capeline top is excellent. Need to get some lightweight pair of salopettes to be worn most of the time, side zips essential.
Pack - need lightweight assault pack. Big pack is too heavy, how small and how light can we go? How much does big pack weigh? How much does Andinista weigh? What cheap options do MEC offer?
Screws - buy more cheap Ti screws, a very good otion.
Heavy items to thinks about: tools, ropes, pickets (minimum)
1 0 or 2000m leave US 2 3500 arrive Cuzco early pm 3 3500 buy fuel, sort out transport to Tinqui 4 3800 drive to Tinqui 5 4?00 hike to Pacchanta, short walkabout 6 5000m,4800m hike to Ticlacocha 7 4800m hike to base camp 8 5100m,4800m establish camp at base of route, hike down +1 rest at base camp 9 5100m sleep at high camp, get up early 10 5800m summit and down +2 rest +3 get into position +4 second attempt 11 4400m 1st day out 12 4000m 2nd day out 13 3800m 3rd day out 14 3500m fly out of Cuzco, evening flight out of Lima 15 0 back in US 15 days ABSOLUTE MINIMUM 19 days two chances + better rest