I picked mine up from my local Riceshop

they usually go as H4 Angel Eyes conversion, mine was a made in china brand that I can't remember.. Phillips makes a conversion too that's not as pretty but still uses H4 bulbs, I know you can pick these up at autoparts stores here in Canada, give it a try in your area.
Tokyoracer, mine didn't fit properly either.. but its easy. screw the 2 screws on the top of the metal holder first, then screw the ones on the bottom slowly until the metal holder stretches slowly and fits overtop.