That quilt kit looks interesting and I do know a gal that sews everything under the sun. Will look into it. The only concern is the toe box, but there may be a way to design around it.
As far as quilt vs sleeping bag, a bag is too confining for me. I have a really nice bag that will get me down into the 20's, but it is simply too confining, especially in the foot area. A quilt allows for better heat regulation and certainly doesn't restrict movement during the night.