You have to be careful about batting. Anything thick will not drape properly. Silk batting is supposed to be wonderful, but it is pricey. Someone mentioned flannel, which is a great alternative; just be sure to wash and dry the flannel twice to make sure it isn't going to shrink your jacket out of shape the first time you wash it.
I haven't made a quilted jacket (don't do well with sewing patterns) but, if I were going to make one, I'd quilt pieces a little larger than the pattern pieces.