We will have between 5 and 100 shops. What we are looking for is away to easily update all the products in each shop and not allow the cost to be changed by the admin of each shop as well as not let them add products - other than that they have control. I have seen two multi shop add-on's but I don't think thats what we need.
I have not installed/setup ZC because we would like to have some idea that there is away to accomplish our goal before we start.

Any advise or suggestions?

Thanks!