If you want to prototype a hook method - there's the rubbermaid fasttrack (and some other equivalent) that the hooks fit inside the lips on the short side:
http://www.rubbermaid.com/Category/P...nizationSystem
Also, if you don't want to spend the money on the roller chain with tabs, you can stick an 8-32 bolt through the roller chain to transfer motion. You'll want to obviously do a few to reduce the stress on any one bolt:
http://www.buildblitz.com/linear-elevator-concept/