First you need to look at your buget and requirements. Most led fixtures cover a 24" x 24" x 30" deep area so you are looking at a min of two fixtures. Also how you are going to place it over the tank.
I went with a AI Vega color, I really like it and yes I did have an issue with the fixture at first but the company replaced it next day air and had great support. The down side was their means for hanging the fixture it can be expensive, i made my own and saved around $50. In all the flexability of the fixture is great and having the wireless controller is an added +