Neil
I use a Yamaha DSPA1 which I upgraded by using an EZO K5.5, a 5 Channel External Amplifier. I had read a review about the K5.5 which was exceptional some time earlier, but had never seen or heard one, however when I went to audition the Piega system the demonstrator used one in the demo. Fantasic!!! Also it was finished in Silver which again looked stunning as well as the best sound I had heard.
I do not know where you are, but if you get the chance you should visit Audio Illusion which is based near Slough - the guy there sure knows his stuff!!!!!
Baldbod