Im not fussed about audio coming from the gpu, the sound quality from my sound card i assume would be far superior. Going up a model... not happening. I don’t want to spend more than 800 (and believe me, i started looking around the 500 mark).
i already have a HDMI to DVI-D cable that is in use with my ps3 at current (being displayed on my pc monitor). When i go home, the ps3 can go on a tv, leaving a spare HDMI to DVI cable. I think my best shot might be to try one of those RGB leads, like the one in the link, and actually see what it looks like. It says it supports 1080p, but lets face it, im sure its not the first product to lie.
I think my brother has a set on his xbox360, but he doesn’t have a full hd tv, nether the less it still looks sharp on his tv.
i have just realised i missed out an option, sky hd might be able to output via HD Component Cable.
Also, i might try a cable like this

If i could bend that round to the back of the tv without stressing the wire, that seems the easiest option. or even better would be if I could get an angled version of that.
Something like this

I think that would hide the cable round the back