If your local hobby shop can't help, I would just order it from Tower. Prices are competitive, and they're dependable.
http://www.towerhobbies.com/listings/cat-cat-a.html
It's cheaper to buy longer rolls.
If you want to order the books from Model Airplane News, they're at
http://www.rcstore.com/rs/general/li...id=8&catego=BO
Go for it!