I think even the VLC solution won't be perfect as each PC will have a different latency decoding and displaying the networked data. If you really want lipsync then post 3 or 9 are you best options as you're distributing the video signal 'live' rather than the data.
Server: Win7 N | AMD Phenom II X4 3.2GHz | 4Gig RAM | Gigabyte GA-MA770-DS3 Mobo | 2TB+ HDDs | 2x Nova DT | ATI HD 5450 | Mobile Pre USB Audio
Client 1: Win7 N | Dell GX280 P4 3.4GHz |2Gig RAM | ATI HD 5450 | Cambridge DacMagic
Client 2: Win7 N | Dell GX280 P4 3.4GHz |2Gig RAM | ATI HD 5450 |On-board Sound