First off, I promise I don't work for Harriet Hargrave; however, I took one of her classes and she picks the batting to go with the quilt (who / why it was made for; how it is going to be used; what you want the finished quilt to look / feel like). That said, if you go to her website
http://www.harriethargrave.com/default.asp and click on Products, then on Batting, you will see that she has a Batting Sample Set. She sells 14 different types of batting in her store, and these sample sets will let you try each of the battings before you buy (small set contains 1 piece of each, large set contains 3 of each). It was amazing the difference in feel of some of the battings, and this gave me a chance to quilt on wool batting, something I'd never done before. So you might want to order a set and try your quilting on each of them. Then, if your LQS doesn't carry that batting, you can always go back to Harriet's site and order from her.