You only want the fusible on one side of the stabilizer (at least I never fuze the blocks to anything other than the stabilizer). Joann's frequently has it on sale -- and you usually get a 40% off coupon in the mailer. I never pay full price for stabilizer.

I agree, the fusible interfacing is the best way to go. You have to be careful using spray adhesives, they can gum up your needle and make it very hard to sew!

Good luck!