Daniel Stern's site (which you linked above) is the best I have ever found for lighting information.
Another good site is
http://www.rallylights.com/. They also offer headlamp conversions and their prices are competitive.
For the money (and results), I would do the relay/wiring upgrade and upgrade to Hellas (item #H50061 at Rallylights). Personally, I prefer the Cibies that Stern offers, but Hellas are also excellent and significantly cheaper.