so i bought this
and this
the pad slides into a pocket on the underside of the bag. the bag has no insulation on the underside (as the insulation is compressed and worthless when sleeping on it, anyways), cutting almost half the weight out of the bag. the pad is 2.5" of insulation/air. the pad is rated to 0 degrees, and the bag is rated to 15. together, they weigh 3.8 pounds.
oh yeah, the bag also has a built in pocket inside the bag under the head to stuff clothes, etc. to make a PILLOW!
have fun with the economy, i'll be sleeping soundly far away from civilization.