My Fiancé ordered the Verso Clip-on Reading light with hers and so far she likes it. It just clips onto an existing case. I don't know if she's tried clipping it directly to the Kindle, but I don't see why it wouldn't work.
Myself, I prefer my lighted case, but she just had to order a LeSportsac case because she likes the design
Give me leather any day.
http://www.amazon.com/Verso-Clip--Re...4737719&sr=1-1