Unfortunately you can't just replace bulbs with "HID replacement" bulbs as these types of lighting systems require much higher voltages than regular halogen devices. You'd need to spend a significant amount of $ to get a true HID system.

I don't have any direct experience with regular bulbs that give the 'HID blue' look, but I believe many of those are just brighter halogen bulbs with a tinted coating. You may get the look you want but the problem is that the color of the resulting light is in a range that the human eye is less sensitive to. So - you end up with brighter light that ultimately reduces what you're able to see.