Re: SiverStars ?
Years ago I ran Silverstars for headlights (in the days before cheap and effective HID kits). They are brighter, initially. However, they dim out VERY quickly in my experience, and it's not long before they are dimmer than standard Halogen headlights.
A worthwhile thing to look into may be HIR bulbs. Initially designed to be a cheaper alternative to HIDs, that sort of fell apart after HIDs got cheap. HIR bulbs are still seeing limited use (the new Edge Sport for example uses HIR bulbs instead of HIDs... to keep from crossing into the Lincoln MKX's turf).
Anyways, optically they're supposed to be nearly identical to halogens, just brighter. That said, there's something to be said for housings being designed for a certain light output, and not seeing the best results if you exceed that output.
Honestly, I would recommend buying a real HID kit, and retrofitting a set of projectors into the halogen headlights. The cost on projectors and HIDs has come down so significantly it's honestly the easiest/best way to go.