Hi Pete,
here in Germany are LED base plates available. They are made of black plastic and have a number of 8 LED's in the middle, you can choose between white, blue or red coloured LED's. They work with a small trafo and cost something around EUR 30.00 to EUR 40.00.
Measure of the base plates is smaller than the crystal, but that's no problem - the crystal is heavy enough to hold itself in place - and if you dont trust you could build a bigger wodden plate around.
To see most details, I prefer the white LED's - but the crystal looks also very nice when lightened in red.
Cheers,
Volker