Ambient, dual-source (daylight & LED) kitchen lighting

I've been trying to think of a way to get better lighting in the kitchen. My first thought was to have all the tiles at the back of the worktop glow softly, to cast a pleasant, ambient light over the worktop - as opposed to overhead light, which means you tend to cast a shadow on what you're doing. This is probably a bit complicated - all those tiles would have to be wired in individually, so my next idea was to replace the tiles with a single large sheet of semi-opaque (cloudy-looking) glass with light sources behind it.

The semi-opaque glass would have a 5mm air gap behind it, and then a mirror behind that. Light would shine into the air gap and be reflected and diffused over the area of the glass, escaping through the front as a soft, ambient light. During the day, natural light would be fed into the air gap from a light pipe (basically, a mirrored tube) perhaps run down a disused chimney (kitchens in older houses in the UK often have disused chimneys). During hours of darkness light would be fed into the bottom of the air gap from white LEDs (or coloured LEDs potentially) and fibre optics hidden in the dead space behind or under the kitchen units.