Well, the worth depends on what you want them for. If you just want brighter headlights, then go with the sylvania silverstars. They will put out plenty of light. But if it's the bling you want, then the worth is totally up to you. I think it would look cool, but IMHO, I could better spend the $400 some odd bucks (how much Iv'e seen the HID conversion go for) on engine improvements.
EDIT: And welcome to the TCCA man!