Both Snugpack and Arktis have bags that fit your bill here.
I know folks that love their Snugpacks and I have an Arktis Halo 3model that's served me well in lots of different locations and conditions for a number of years.

They're both military models, so they tend to have some durability. The Arktis model has a waterproof foot area, accommodates people up to 6'4", and weighs about 2 lbs.