Go with a down bag. It'll last longer and be more comfortable sleeping in it and carrying it.

I use a large 3L size Nalgene Cantene (holds 4L) to hold extra water when necessary. It also makes a decent pillow. Gatorade bottles are lighter than Nalgenes.

I use a 2L Open Country aluminum pot which is around 7 oz with lid and $12 or so. I typically only boil water in the pot (to avoid needing to clean it), and eat or drink out of a Rubbermaid TakeAlong (1 oz weight, 16 oz volume)