The best solution might be adding a template stored on a network shared or something so users can edit the signature and add it to Outlook manually.
The signature is stored in C:\Documents and Settings\%Username%\Application Data\Microsoft\Outlook
and I believe, but not certain, it's in the file: Outlook.NK2
In any case it is not readily editable.
You can also put that template in that folder above but this should not be accurate.
Definitely, I would just give them the template and let them add their info and let them know how to add it in Outlook.
Hope this help!