Thanks for the comments fella - the head unit, well it would be nice to keep it but I wasn't really planning on it as there isn't the space unless it went in the glove box and I just hink it'd be a bit pants there to be honest.
I've got a Dlink USB tuner and already have amps in the car. Been given an Audigy sound card to test too when I can get a suitable riser to fit it in the case.
I suppose I could do away with the DVD drive and it would make life so much easier but I thought it would be a useful addition and I don't want to admit defeat, although I may end up doing so in the end.
You've got me thinking now if I should just do without and take the easy life....
If I could find some very small bearing drawer runners that would be a start....
I do plan on adding a USB GPS device at some point - no rush as I certainly don't need it over here! Useful for trips across though.
Was going to have a USB extension cable coming to a few ports on the dash too so I can plug in wifi dongle etc.