http://www.zellestyle.com/catalog/1337.html It'd be interesting if we could somehow ask for dud parts (that do not work right but look fine) from a nearby parts manufacturer. Come to think of it, that'll be a way to use parts that would otherwise be discarded.
IDK if it would be worth your while to try and get "bad" or "discarded" parts. might as well go for bulk on EBAY.
a led one might work, but where would you put the battery? and also, if you were to wre one up like the cascade one, it would look sick if it had a microconrtoller, changing it from white to blue in a wave effect
you should get your gf one and make it a remote shocker to send some current thru her every time she pisses you off