If you are considering LED
for your tank you will have to double up on the fixtures. Most of these LED
fixtures will not have the penetrating power to get enough light to the bottom of the tank. If you are going to stick with low light plants you might be able to get away with one of them. The thing about most LED
fixtures is they are designed to sit directly on the tank which means they will not have a good spread being that close to the water. I run LEDs on all of my tanks. I built them myself and have them suspended 10 or so inches above the water. I also use 3w LEDs and most of these fixtures do not.
Like I said in a previous post it all depends on what you want to put in the tank. For the money I would look at a Finnex 24/7+ this is more than double your $50 price point but you will get a lot of bang for your buck!
FYI I have two of the beamswork leds. They work well for small tanks but will not do much for your 75g.