04-05 Impreza is an H1 for the high 9005 for the lows and H3 for the fogs.
I am using Hella YellowStars in the heads and the fogs.
as far as white i would recommend some of the other companies known more for style. ie PIAA, Polarg and Raybrig. these are more "high end" bulbs the ones that hank mentioned are usually more functional but lack a nice "white" color. the ones i mention have the color AND the functionality.