Ok, thanks a lot for the help and suggestions. My old school (2007) TV & blu-ray don't believe in such things as ethernet so I think my best way forward will be something like a Netgear Neotv for the video & music streaming (I was thinking to kill 2 birds with one stone and get a home cinema that could stream but most I've read about claim to only stream audio from a NAS). I believe the Sky box can get iPlayer, 4OD etc. Depending on how I get on with HDMI connections etc it might be worth replacing the stereo with a home cinema unit anyway (reasonable quality seems much cheaper than when I last looked 10 years ago) and then the stereo can move up to the office and be used as an overly posh pair of speakers for the computer...
Off topic but out of curiousity does anyone use Homeplug for network connections through the mains sockets around the house?