I may get flamed by the Ken Land haters, but here is my experience and a few options you can consider.
In 2008, I ordered a pair of the X600's from Bullet Lines. One came damaged, called Ken, and he quickly replaced it. Had them installed on my 04 210 and never had an issue with the lights. My water wasn't the clearest, but I was happy with the output for 2 lights with 6, 1 watt LED's.
http://www.bulletlines.com/Underwate...hts-p/1020.htm
(see if think still works
http://www.planetnautique.com/vb3/sh...er-LED-s-Pic-s )
A few years later, and 2 boats later, I am looking at another set to install in my 06 VLX. I have considered the X600's again, but the price has gone up since 2008. I am not in the crowd that thinks its worth spending big money for the Shadow Casters, and am completely happy with a cheaper set of lights. I recently came across these:
http://www.oznium.com/6w-flood
It got me thinking, 6 watts sounds offly familiar. So I went back to Bullet Lines website and saw that they sell a brass set that is identical to the ones on Oznium's website, but for $100 less.
http://www.bulletlines.com/under-wat...ght-p/1029.htm
I have no experience with the Malibu OEM lights, but as you can see above, with enough of them, they look good (
http://www.bakesonline.com/detail.aspx?ID=828). If you have a budget of $500, you may want to consider the lights on Oznium's website, and also the Malibu OEM lights. I don't have direct experience with the Oznium lights, but as I said, I can't see much difference between those and the ones that Bullet Lines sells.
Good luck...