Hello again TheCaptain,
Like bigboss and BenLaw, I'm struggling to understand how the cabling for your relatively straightforward proposed system can possibly come to anything like £400! Can you do us all a wee favour? Please list all the cables that you will need, linking which components, and the length of each cable. For instance, (a) HDMI cable from Blu-Ray player to receiver, 2 metres; (b) Loudspeaker cable from receiver to left surround speaker, 8 metres; etc. Do that for ALL the cables that you think you will need. I myself tend to use HDMI, optical digital audio and VGA from Lindy electronics http://www.lindy.co.uk but that's partly because several of my HDMI, optical and VGA cables are 15 to 20 metres long (to go between my three rooms), and Lindy's long cables are very reliable and just keep on working, and are not too expensive. For instance, a recent purchase was of a 20m HDMI cable, this one http://www.lindy.co.uk/20m-premium-standard-hdmi-cable/41118.html . £72 for 20 metres is not bad. Lindy do shorter cables also!
Incidentally, I'll endorse the spirit of what bigboss said about using cheaper cables, even within Lindy's own range. Once upon a time, about four months ago, I wanted two 2m HDMI cables, and I was feeling flush then. So I bought two cables, both from Lindy. This £9 one http://www.lindy.co.uk/2m-premium-high-speed-hdmi-cable/41112.html and this £65 one http://www.lindy.co.uk/2m-premium-gold-high-speed-hdmi-cable-with-ethernet/37421.html. I connected them using the twin outputs of my Yamaha RX-A2010 (and no, I don't have shares in Yamaha!) to two inputs on my LG 60PZ950T television in the kitchen, a big enough screen to show any differences. And, I sense you asking, could I see or hear any difference between the £9 cable and the £65 cable, which are from the same manufacturer?? Er, no.
For speaker cable, I've never done any comparative tests with other cables so I can't say objectively how good they are, but I use Richer Sounds' Cambridge Audio SYMPHONY 400 cable http://www.richersounds.com/product/speaker-cables/cambridge-audio/symphony-400/gale-symphony-400 , at £2:49 per metre, in all my rooms. I also use Richer Sounds for coaxial digital audio cables and AV interconnects.
Still can't think how you could get to £400 .......