The Cloud CX-A850 8 channel amplifier is much used and recommended for HW installations so in case anyone else is interested there are a few used ones available on eBay (UK) at the moment at £230 or offer (normally about £1,000 new). Looks ok (not anything to do with me tho - I bought one).
http://www.ebay.co.uk/itm/322439749131? ... Swx6pYuDfy