So the quilt had just come out of the sack, hence the crumpled-ness. I'm pretty happy with how it turned out. Originally I was going to do a permanent baffled circular footbox but after trying to design it and all it's dimensions (accounting for loft of the quilt by making the inner disc of the footpiece 4" smaller diameter, adjusting the lengths of the top and bottom quilt fabric at the foot end, joining the two together, etc.) I decided to just go with a drawstring closure. I haven't made a draft stopper yet, as I'm only going to use it inside/on top of my winter bag for super cold camping for now. When next summer approaches I'll add some things such as pad straps, draft stopper, etc. The drawstring closure is shown, the knot is just a placeholder for now.
I also included some pictures of my makeshift dry sack, I just used silnylon and sealed it. For the top to keep the package light I just used a ring of grosgrain with small 1/2 inch side lock buckle. My problem is that the grosgrain isn't quite stiff enough to roll down well. Anyone have ideas or done this in the past? I found some stiff 1/2 plastic at the local fabric store, the box had a picture of a corset on it, so I'm guessing it's used as some sort of structural support for fabrics, maybe I'll sew a piece of that inside next time I try a dry sack. Also, I need a strap on the bottom. With the seams sealed pulling the quilt out creates a vacuum and makes separating it from the stuff sack difficult without anything to hold onto on the sack. Again, if anyone has tips in this regard I'd love to hear them.
Oh yeah, quilt is 46" at the top, 36" at the foot, with varied baffling thickness. Before stuffing it, I measured the loft, it goes pretty steadily up from 2 1/4" at the foot to 3" at the top :) toasty insulation for only 16.5 oz measured weight (with seam sealed dry sack, but without straps, hardware, or other future additions). Special thanks to Mikeinfhaz's posts on hammockforum and Jonathan Duckett for the great references.
p.s. for anyone looking for sources of materials like I was, I got all the fabric, netting, etc from Quest Outfitters. Black is 1.1oz silnylon (2nds) and blue is 1.1 uncoated ripstop. Down is from from Speer Hammocks (advertised as 900 fill power, but certification shows 927 c.i. with 5-10% variability which seems like this would put it at 835 minimum fill power). Both suppliers were fast and excellent service/assistance.