You might want to look at running SageTV on your server PC and then getting a Sage HDTheater extender to put next to each TV. That way you can have full control over DVR functions/DVD rip/BR rip playback from any TV in the house. They do not do anything with Windows media center, but run the SageTV front end instead.
If the idea of being able to fully control the DVR system (not just play a TV show that has already been recorded onto the computer, but check the TV guide, schedule recordings, delete watched shows, watch/pause live broadcasts, etc.) from any TV in the house is appealing to you, a SageTV setup has a lot of capabilities that you can’t get with regular boxes like a PCH and such.
Sage extenders also support full DVD rip playback with menus and subtitles and if you have a copy of AnyDVD on your server computer, the extenders can play the DVD/BR disc wherever they are in the house from the disc drive in the server PC. If DVD rip playback is important to you, then it is a significant difference compared to using an xbox360 as an extender with windows media center, as (to my knowledge) the xbox360 still does not support full DVD rip playback. One thing the xbox360s do provide that the Sage extenders do not is the feeling of sitting next to a hairdryer as it prepares to take off, as the Sage extenders have no fans and are completely silent.
Sage extenders do have limitations in BR/rip disc playback. Although they are capable of parsing the BR disc directory structure (so you don’t have to monkey with converting files to mkvs or worrying about converting forced subtitles, etc if you don’t want to) they only play the main movie. They do not support full menus in BRs (yet.) Further, they will only pass the core audio (DD, DTS) track from the Blu ray, not the advanced TrueHD or DTS HD-MA tracks. So if *full* Blu Ray capabilities are a must, they may not be your complete solution.
If you’re going to be setting up all that system, it might be worth a look to check out SageTV. www.sagetv.com