very nice, have you got or do you want a surround sound system as that is really the back bone of my system
also you are limited by the connections of the sky box (presume the reason for your installation is to hide all wiring), the tv has hdmi, vga, scart and component at the rear. but the sky box only supports scart and component.
If you didn't want to get an amp just yet I would suggest running both scart and component cables, that way you could pick the one that offers the best quality connection from your sky box, unless you have time to test it all before its all built in, if you will not have access to the wires in the future its probably worth chucking in 1 or 2 hdmi cables for piece of mind

This is my current setup with what I will do once I have found a suitable amp.

media centre optical out into amp, hdmi out has to go the tv at the mo as the amp doesn't support hdmi - but will be hdmi to amp
sky +, optical out to amp, s-video to amp
then s-video to plasma - with new amp will be hdmi
WII just straight plugged into tv, will be looking at getting it through the new amp

From the sky box I will be looking at distributing the signal to each room with a tv, all pc's networked and most probably a nas box for file storage and sharing