Aftermarket housings are generally much worse than OEM in terms of light output.
Your best economical solution is, as posted above, put glass lenses on your OEM headlights. Putting HIDs or LEDs in those housings will lead to light going all over the place. Stick with the H7 halogen bulbs - go a little whiter there if you like; keep in mind, though, that *too* white (like 6000K) is terrible on wet pavement - the road all but disappears. Philips XtremeVision or Sylvania Silverstar bulbs are solid choices.
If you want a serious upgrade, then you need to buy/
build some projectors - the housings with projectors in them that you find on eBay or Amazon are absolute trash (ask me how I know
). If you want a winter project, though, buy one of those housings, take them apart, replace the bulb or projector with a decent quality HID projector, put in some good-quality bulbs (CNlight; Morimoto) and decent ballasts - then you got something.
If the bulbs/ballasts are like $30-$40 for the set (two bulbs, two ballasts)...that's not gonna cut it. "Decent" costs closer to $100.
4500K or at most, 5000K color temp is best for all-conditions visibility. Much higher than that and wet roads start disappearing.
You can do a fairly decent upgrade/retrofit with just some
mini-H1 projectors that screw into the reflector bowl of OEM headlights. The problem with those, though, is that they protrude out the back - won't be able to get the rear cover back on. It is possible (I've done it) to work around that, but it is a bit of a kludge. Going to some better projectors (like FX-R with D2S bulbs) is another significant improvement from those.