There is another way to the above...
Free delivery and returns on eligible orders. Buy Goodmans Module WiFi Audio Adaptor with Spotify Connect - iOS, Android Smartphone and Tablet Control at Amazon UK.
www.amazon.co.uk
Comes with interconnects too. I am running one of these and though the interface isn't the best, it works...
It will find files on NAS or on devices linked to the home WiFi, it will stream, and all that for under £15, delivered, with warranty....