Thanks Ian, they seem to be well reviewed. However I'm not sure if its over kill for what I'm trying to do. Please see the below diagram the proximity from tv to box is very close..
I'm converting my loft and the av stuff will be hidden in a cupboard within the eaves.
My original plan was to have a roller door that could be opened when watching tv but they are hard to buy and expensive.
If I used the PowerMid it would basically be sat right next to the TV and VM box. Is there not some kind of an extender that would go directly into the back of the vm box?