Unnamed collections from multiple datasources


Im writing an application that gets its data from MS SQL Server via a REST Api. There are 15 databases that make up our organizations development and testing environments. So in theory 15 Clients could be accessing 1 database each if they were all using a separate environment.
So far Ive been using unnamed or unmanaged Collections and get the data from the corresponding database that aligns to the users environment. What Id like to do is accept a request from the client, fetch the data and publish the results back to the individual client that requested it using a publication. Being able to use the ready() function would be really useful not to mention others.
Is there a package that solves this problem where the data source can be different for each user, or some other technique I should be using?
Im currently reading Publications and Data Loading any help appreciated.