I've taken a bunch of pictures (attached). While doing that I discovered 3 things:
1. Although it's using the original fluorescent bulb power supply, the bulb itself is a newer LED one
2. That doesn't prevent it humming
3. The length of the cavity for the light is 12", and there's enough depth that under-cabinet LED lighting will fit (with appropriate padding)
Of course, having said #3, it's a matter of finding one that doesn't have the bump in the detector bump. A friend from Apple checked with collectors there, and one of them uses this:
Though it has the detector bump so I'm not sure how the lighting would look.
Basically, I'm still after a good solution, especially one that lets me keep the switch from the original control (see the pictures)