Aha, I do like a good batting discussion
. Hobbs Tuscany vs Hobbs Heirloom Wool - my personal preference is the Tuscany, it is softer and has slightly more body to it than the Heirloom, but it does need hand washing rather than machine washing (according to Hobbs). It's beautiful for machine or hand quilting. The Quilters Dream wool is also gorgeous, it has a higher loft than the Hobbs, but it can be machine washed (according to QD).
Quilters Dream Orient (which was also mentioned on this post) is an extremely dense and flat batting, the roll of it weighs a ton, compared to some of the other battings. I haven't used this one, but would imagine it would be good for a wall hanging or anything else you wanted nice and flat.
Polyesters are some and some, at the end of the day you get what you pay for. I like Hobbs Polydown which is nice and light and soft. Quilters Dream polyesters are more felted and firmer, they give a nice finish for a wall hanging. I've used it in a bed quilt recently and it seems a little stiff, but I'm going to wash it soon and see if it softens up any. It was nice to work with and all the layers kept pretty stable.
I'm a 505 spray adhesive fan, I use it for all my quilt layering, be it hand or machine, though if your hand project is big and is going to take a long time you might want to consider tacking as well, as the glue will lose its stick and disappear over time (you'll be fine for a few months though).
Cotton battings have their pro's and cons as well, I usually advise not to use cotton if it's a quilt that's going to be folded up for a lot of its life, as cotton holds the creases much more than wool or poly. It's also heavy, so stitching and washing a large piece can be very hard work. However, it does give a nice flat finish, my particular favourite is the Quilters Dream cotton Select (mid loft).
There's a great resource on the web on battings, I'll try to find the magazine it was mentioned in and get back to you all.