Personally I'd go with:
Linky
Chris is a great guy. I had their kit for ~2 years now and had 1 ballast go out. Chris got me a new one for free under the warranty in less than 3 days. Lights looked great; always got compliments on them.
You can also do the Ebay ones. Granted some people might say their aren't safe but thats your call. Also you can do TheRetroSource.