Whole House/Multi Zone Audio

["Phil" <theatre@xxxxxxxxxxxxxxxxxxx>]

Following on from the recent query about whole home audio, I am
considering putting together a multi zone audio system similar to
Sonos. The functionality required is this:

Audio (and ideally video/dvd and photos) stored on a server
Controllable from any room in which the system is installed, without
keyboard/mouse
Different media playing in each room
Ability to sync across each room (for parties etc)
Cheaper than Sonos (otherwise there is no point in doing it)
Runs on both wired and wireless network as required depending on if
cabling is already installed
No TV control is required as (being in the UK) this is handled by Sky+

My current thinking is to install a trial system in 2 rooms: lounge and
master bedroom, and use second hand P3/500s or thereabouts - these are
available on ebay for abut =A320, without OS.

Lounge:
PC would act as main server and lounge client, supplying audio to
surround sound amp. A TV out card would allow the TV to replace a
monitor, and allow dvd to play through the TV (but unlikely to use this
feature in this room due to the existing surround sound setup). Control
would be through remote control navigating via the TV. This can be
wired to the nearby router/broadband connection.

Bedroom:
PC acts as client, supplying audio to amp and speakers. LCD TV already
has a VGA input. Control is via a touchscreen mounted to the side of
the bed (requiring a VGA splitter to allow both screens to be used).
This will probably need to have a wireless connection.

All ripping etc to be handled by main PC running Win XP in office,
which can also access server to supply music to office.

I would have thought that P3s have more than enough grunt to manage
this task, as anything tricky will be done by a much better spec'd
system. As for OS, unless I find second hand pcs with one installed, I
would be using Win98 (I have a number of copies lying about that are
not used) or a Linux distro.

My questions are these:
Does anyone see anything wrong with the above?
I cannot see how to get this system to sync zones when required - is
there a way to do this?
Which OS would people recommend?

Thanks for your help
Phil