Lamp Brightness

I previously posted about getting some new projector headlamps, not quite sure regular projectors or AE's. But, I was wondering if after buying the lamps can I still install better bulbs to get the brighter plus the blue tint in the light. I heard somewhere I may not be able to upgrade the bulbs for some reason. What is the best way to go about getting the brighter shine with the tint in it? Projectors with new bulbs...stock with new bulbs.....what should i do?