Send an email to landsharkz ... they did a coin with an Enterprise on it (you can see one that my nephew and I have been dipping here). Maybe they can give you some tips.
Found this on Viacom's website.....
5. Trademarks, Copyrights and Restrictions. The Content is owned by Viacom; Viacom's subsidiaries, divisions, affiliates, directors, officers, partners, employees, suppliers, licensors, agents, and assigns (collectively, the "Viacom Affiliates"); or third parties, and are protected from unauthorized use, copying and dissemination by copyright, trademark, publicity and other laws and by international treaties. Nothing contained in these Terms of Use or on the Web Site should be construed as granting, by implication, estoppel or otherwise, any license or right to use any Content in any manner without the prior written consent of a duly authorized employee of Viacom or such third party that may own the Content displayed on the Web Site. ANY UNAUTHORIZED USE, REUSE, POSTING, REPOSTING, DISPLAY, PERFORMANCE, SALE, FRAMING, COPYING, REPRODUCTION, MODIFICATION, PUBLISHING, REPUBLISHING, UPLOADING, DOWNLOADING, TRANSMITTING, DISTRIBUTING, DUPLICATING OR ANY OTHER USE OF THE CONTENT IS STRICTLY PROHIBITED WITHOUT THE PRIOR WRITTEN CONSENT OF A DULY AUTHORIZED VIACOM EMPLOYEE. As a user of the Web Site, you agree not to use the Content for any unlawful purposes and not to violate Viacom's rights or the rights of others. Viacom reserves the right to object or otherwise take action against any such use.
So I don't think the risk is worth it without permission, I did contact Viacom and am waiting to here back and see what they say about it, could be awhile though.