Just a note: Oftentimes if you become buddies with a quilt shop owner, she will cut jelly rolls specifically for you! Right now I am completing what is called a "Jelly Bargelly," which is a Bargello made from a hand-picked jelly roll of 17 different fabrics (3 of each), so my "customized" jelly roll is the standard 2 1/2 inches, but it includes 51 strips. The colors graduate from light to dark.
Hope this helps1