Having just looked, the TV has RCA, the DVD player has RCA & Coax.....I don't have Sky yet so don't know what that has and the PS3 just has Optical.
If the PS3 (and DVD player and Sky I assume) are plugged in via HDMI, will having the amp just going to the TV get the sound for those too?
Or is it better to have the HDMI just for video and then the other devices plugged directly into an amp for sound?
Edit: Picture of Sky+ HD box
http://upload.wikimedia.org/wikipedia/commons/6/65/Sky_hd_001.jpg