The key to a Workshop is not what kind of work you will have the students submit, but your assessment strategy. An assessment strategy determines what the students assess, how they assess, whether they must agree on their assessments, whether their assessments must agree with yours, and how much of their grade depends upon completing assessments.
As you set up the Workshop, be sure to think about how you will tie everything back to learning objectives and how your assessments should be measurable. They should also indicate to the student where there may be gaps in skills or knowledge. In participating in the required tasks in the Workshop, students will learn from each other as they collaborate and then assess each other's work.
If the work that the student produces is the most important part, you may as well use a simple Assignment instead. It is the assessment strategy that makes a Workshop different from the other modules.