Integration with on-demand manufacturing sites

I generally work with small nonprofit groups (mostly state-level) who do not have the resources or demand to maintain a physical inventory of items. I've set them up on sites like Cafepress.com as well as zazzle, printfection and spreadshirt, but it would be nice to offer them the ability to integrate these products more closely with their Drupal-powered site. I know at one point there was a Cafepress module, but it seems to have fallen into disuse.

I'm curious to know what logistical issues there might be in developing such modules, and whether there is a demand among other organizations for this kind of feature. I envision being able to create products from a variety of on-demand manufacturers, and once the order is placed, the backend will register the orders with the appropriate manufacturers to minimize any overhead that the organization has to deal with. This also allows people to mix and match on-demand manufacturers, as some are better than others for certain products.