The good news is that there are more quilt options now than ever before. Nunatak, Jacks r Better, Katabatic, Golite, and a number of individuals that on these forums like Tim Marshall, that can make you a custom quilt.
Another couple of options are purchasing a kit from Thru-Hiker or sourcing the materials and building your own. Another option is converting a sleeping bag. I have turned a WM Highlite to a summer quilt that weighs 14oz and is warm to 40f and a bit lower with clothing. Believe me, it took me a while to cut into such a nice new bag, but I got it during the MooseJaw sale and it seemed to be made for the conversion. I have also purchased a Golite Adrenaline 40f with the top zip for my son that will be converted as well. Converting the right bag can be much easier and cheaper than a kit, and less expensive than a ready made quilt.