Flannel back will add weight but it will be nice and warm. Thousands of bolts has many wide backs to choose from
http://www.thousandsofbolts.com/inde...category_ID=26
so does Hancocks of Paducah (more expensive)
http://www.hancocks-paducah.com/Item...ng-Sale--m-639
Edited to add that your quilt came out very pretty.