[Skillian]

Thanks for responses guys.

I actually already have a 10m DVI-HDMI cable - it cost me about £15 from eBay and has never given me a single problem.

The wireless keyboard thing is a good point. I think I'm going to have to dangle the dongle through the hole in the ceiling, and I'll have to do that with my 360 controller wireless receiver too.

The other issue I thought of was getting sound both upstairs and downstairs, but luckily I use optical downstairs and analogue upstairs, so it should just be a case of switching the digital connection on or off (through the drivers) when moving between computers.

I received a 10m optical cable through eBay today so I'll probably try putting this altogether this week. I'll let you know how it turns out...