My first vote would be for the Giesemann Spectra. Second suggestion would be the ReefBrite Hybrid Pendant. I have no personal experience with the Spectra, but have heard nothing but good things. There's a reason the Giesemann brand is regarded as one of the nicest lighting brands on the market. I have used the reefbrite pendant on a 25 gallon cube and like it a lot. I would certainly use on again. The only issue with the reefbrite is that it is not the most visually appealing fixture, which is why I voted for the Spectra first. Not only does it have a reputation for being an outstanding fixture, but it also looks the part.