Hi Aaron,
Yes, it is possible.
You could use Data Sink of type Property to generate a custom request containing an arbitrary number of values that you're loading in a DataSource Loop. Prefix would contain the initial part of your web service request, the Suffix the end part, while Content would be the part that would need to be repeated for each ID you have loaded via DataSource.
The resulting property you can use as raw text representation for your request.
Let us know if you managed to build a request composed of multiple IDs.
Cheers!
/Nenad Nikolic a.k.a. Shonzilla