Story Supply company produced these great little notebooks that I've been testing out, and I gotta say I've been really impressed! They have stood up to lots of different drawing tools. Check out some of the sketches from the tests:
There is a mix of pencil, color pencil, pen, marker, even opaque white out paint, all handled well by this little gem.
I may join forces with these folks.... Stay tuned!
PS- you can find them here - http://www.storysupplyco.com