If your exhaust is physically fine and you just want some more sound, why not try the ultra cheap option of just removing the back box. Several owners have done this on here, their cars sound really good. Simply removing that back box releases the proper V8 sound.
I don't know if there are any sound clips.
There was a set of replacement pipes in the For Sale section for £100
http://forum.a8parts.co.uk/showthread.php?t=10441