Decor Bond and Fast2Fuse are pretty much the same, good and sturdy, sewable but not the least bit floppy. Works well for fabric bowls (not the microwave kind, the decorative kind), so would work for bags, too.
I asked at my LQS one day if they had either one and, surprisingly enough, they did...hidden away in a closet. You might try asking, just in case yours sells it "by request only" like mine does.
