I can't imagine how a site like that could stay up to date, especially when you consider how many stores there are and how much merchandise the large ones (like the Emmporium at MK) have. Josh at easywdw.com will often do merchandise updates (he just did one on 2015 merchandise), but I think that's (and the Disney parks section on
disneystore.com) going to be the best you're going to find.