Skip the whole stocked shelf thing entirely. Have a website setup that customers can build a shopping cart, then just show up and pickup their "pre-bagged" groceries. The benefits to this are obvious.
1) No shop lifting. 2) Car friendly (you could have multiple drive-thru pickup lines) 3) Convenience for the shopper (saved lists, common items, don't have to walk around the store) 4) The store, could just effectively be a warehouse. 5) Possible to automate almost all of the work.
And before you say "what about produce?". Well, you could have a automated "imaging" station upon goods receipt that customers could use when building their cart. Or, offer really good return policies. Either way, the convenience would far outweigh the produce problem.