Hey, try this sleeping bag instead Its 70 dollars cheaper .5 lbs heavier and packs down to the same size as the one you chose. Also when a bag says 20 degrees, it means survivable and that temperature. The comfort zone is usualy 10-15 above what the bag is rated at.

For the stove, I think it'd be easier, cheaper, and lighter to make a cat stove and use yellow HEET as fuel.