I used these stick on strips from the auto section of Fred Meyer. Probably similar items at any auto parts chain store. Spliced the wires with a 12V power supply block from an old cordless phone. I think the block said 9V, but when tested it was actually putting out 12V.
Only thing I can say against them is that I have no idea what the actual color value is and they make a bit of a spotlighted row if aimed directly down. So I pointed mine up into the reflector to diffuse the light a bit.