What does Remote Web Workplace in SBS offer that Terminal Services on SBS wouldn't offer? It seems to me that giving clients remote access via Terminal Services to an SBS server offers a duplicate of their local experience. What would be the reasons to use Remote Workplace instead?
RWW offers remote access to the local workstations where people have their own programs and potentially files stored.
You COULD add a FULL Terminal Server (Remote Desktop Server), but that is DOUBLING your license costs if you already have the workstations in the office.
Perhaps I'm misunderstanding your question and if you elaborate on what you want to do and what you have I could offer better comments.