Okay... let's discuss light selection...
In my opinion, there is no "correct" light.
When I choose a light or if I want to know if an existing light is adequate, the things I look for are:
1. Light Spread - This is the area that the light covers in the tank. Think of it this way... if you have a flashlight on and pointing at a wall, as you get closer to the wall, the size of the light on the wall gets smaller. As you back away from the wall, the size of the light gets bigger. This is the light spread. Getting your light to cover the entire footprint of the tank can be achieved by raising it higher above the tank or bringing it closer if the spread is too great.
But that isn't enough...
2. Light Intensity - It isn't enough to have light filling the tank. It also needs to be of adequate intensity. While many people like to measure light using a PAR meter, I own a lux meter and use that to determine if light intensity is adequate. My goal is 8000-10000 lux at the deepest part of the tank.
These are the things to look for when shopping for a light.
That being said, wow... I've never seen someone move so fast on advice! LOL