If you have the room I prefer roll batting as many of the packages battings are too wrinkled to use straight from the package - you need to fluff them in the dryer or open them up and let them rest overnight. The exceptions are Quilter's Dream and Hobbs Tuscany which are folded instead of rolled up tight so they aren't so bad.
Wholesale sources: Brewer Sewing Supply, Checker Distributors, Rubenstein & Ziff, Quilter's Dream, United Notions/Moda, EE Schenck, Notions Marketing, Kingsmen Quilting Supply are just a few. Not sure where you are but Google these and find one near you to reduce on shipping costs.