Originally, I went with a set of H4 conversion housings to replace the old sealed beams. That alone did wonders even with the cheap blue bulbs.
Threw on a relay kit and that helped out a little bit more.
Eventually wanted a little bit more, threw in a set of HIDs. 55w, 6k bulbs. The higher wattage ballasts wash out the blue and turned it almost a pure white with a touch of blue.
Ran that for a while, worked amazing, but produced a ton of glare that would blind other drivers.... to the point that my buddies refused to drive ahead of me since they were so bright and lit up all their mirrors and entire cab.
So, got tired of that and went to retrofitted projectors in the conversion housings. All the benefits of HIDs with control over the output and reduction in glare!