I guess my thoughts lean towards the above suggestion .. being able to hook in EnderStorage has some real benefits. If this was possible, it could be linked into a personally coded ender chest. The right setup back at base could ensure content is available from the vendor, and even extract any payment to be placed into a sorting system.
Hey, I have a feature request.
An option to set the "seller" to a name you input, for story maps.
So I can have "Smithy" as the seller in my town in my adventure map and not have it display my user name because I made the map.
This could also have a config option on servers to disallow changing of the name on the server if you want.
Basically, the vending block would still save the original placers name saved internally for permissions and editing of the block later, but it would simply display the other name when looked at by a player.