My snow camping stove is a whisperlite. But for a party of 6 I would not bring just one stove. probably even for 4 I would bring a second stove. Otherwise it's going to be a long haul to melt snow and cook dinner for everyone. I'd go for 2 stoves and I'd bring a 4-quart pot for each one. I use a 2-quart pan for 2 guys and sometimes wish it was bigger. Fuel-wise, my experience has been 1 liter of fuel each person lasts us a week in spring sierra weather (warm days, meaning you can keep adding snow to your water bottle during the day and it melts so you don't have to melt as much on the stove).