UV's are a much better than fit than Ozone for a reef tank.
I rate them above Ozone and well above Carbon.
Carbon is last for 3 main reasons:
1. The constant need to buy it. Plain and simple.
2. To be effective it needs to be changed regularly. New media rinsed etc.
It is messy and a pain.
3. When the Carbon is 'full' nutrients are no longer being taken up.
To make matters worse, the Carbon becomes a trapping area and begins to actually 'cause' higherl levels of DOC's. Being cut by your own sword is not a good thing.
UV's perform a multitude of different tasks. All of which are beneficial.
Certainly you can use too much. A 240 watt UV on your tank would be detrimental.