Not worth it, not even close.
I assume you are talking replacing the stock headlight system.
HID's don't neccesarily last any longer than stock headlights. Plus are you ready to spend $400 for a replacment bulb?
CV's don't have bad lights. If you are having trouble seeing them in the rain, my suspicion would be that they aren't aimed properly, or you are using highbeams. Highrbeams leave a dark spot right in front of CV's, even when properly aimed, and light up further down the road.
Get the aim checked.
Compare the bulbs you have to another CV's lights. Often the bulbs "yellow" with age. Replacing them can give a lot more light.
Mount "fog" lights. to give a wide beam of light directly in front of your car.
HID vs DOT, the aim for Euopean vs US HID's is different, I'm not sure exactly how. But I believe Euro-spec lights are more sharply focused for longer "throw". DOT has recieved bunches of compalints about HID lights, from other motorists. Since there are lots of citizen complaints DOT feels HID lights may be problematic.