How to create a value set or find an existing DFF for a user to look up a person

Requesting direction on how to create a value set or perhaps use an existing DFF for a user to look up a person, and be returned their name and email.
This will be used as a DFF segment in the Expense Report header for the user to select the name for the owner of the report.
The current value set is attached to this SR. It only returns the user name, with no email. This is a problem with people having the same name, which the company does have.
Also, please include directions on how to change the column names Value and Description to something more descriptive, like Name and Email.