BT has the XP version with a Geode preocessor for £590, or bundled with a mouse and USB TV stick for £630,, though it's £800 for the 800MHz Vista version I tested . US pricing is better at $1199 with Vista/XP or $1099 for bring your own OS.
*I know the original Japanese model had a calibration issue and that the Linux drivers may not help you enough here. If I'm using a touchscreen I want Vista for the touch support.