I fitted HID's to my car, but £300 for the bike's a bit rich considering how often it's out in the dark.
I use Osram Silver Star from
http://www.powerbulbs.co.uk/ Personally, I'd avoid blue tints as they (typically) reduce the amount of light transmitted, by blocking the low temp light to make it appear to be a 4000K lamp and fooling the eye into thinking it's brighter.