I'm gradually setting up a 55g too. I looked at a lot of LEDs and I've pretty much settled on the finnex fuge ray planted. It's not outrageously priced works on a dimmer and has a good spectrum of light. That being said I have the fluval planted on my 13g and my plants grow like crazy. I divided a crypt yesterday and got 5 crypts out of the 1. The crypts only been in the tank 4 or 5 months. Unfortunately with the legs it sits about 3" above the tank and does not work on a dimmer. That means I'm getting too much light and have problems with algae. I believe the finnex has a 90 degree angle and the fluval is 120 degrees. The "Build Your LED" lights are 90 degrees too so that's probably fine for a medium light tank. The finnex is also 1/3 of the price of the "Build Your Own" and promises 40,000 hours to the "Build Your Own" 50,000 hours.