Thinking about getting one of these and would appreciate some help. Will the supplied remote control my Sky+ and/or my Panny PW5B plasma? Is the remote a learning remote? What's the difference between this and the 550? Any real reason to pay an extra £150? Does the OSD display things on the TV like volume or input changes? Is it possible to get speaker brackets for rear speakers (or just attach them to the wall?) Thanks for your help.