I think Ozone is a lot better option. you can easily control it with the use of carbon and an ORP controller. It not only makes your skimmer more effective, it kills parasites/bacteria/algae etc, it also makes your water much clearer, thus you get more benefit from your lighting. The key is to keep it all in the skimmer, using carbon on both the water output, and the air output from the skimmer.
UV also tends to add a fair amount of heat to a system. I think both have there benefits, I prefer ozone because it has many more benefits than just nuking bad critters.