Providing a link migh be better. This unit looks alright. I bought one off eBay I still use on my 55. However, a friend often bought the same light and had a ballast issue that almost caused a fire. Although these lights are attractive (in price), I would recommend if you are topping out at 300. For lighting, that you do your best to find such light. I know it's a huge investment, but to be honest, aside from regular water changes, this is the most important part of your tank, because it dictates what you can and cannot care for.
This is the light I'm currently running
Now I didn't pay this dollar amount because I bought mine used from a very good friend. However, this light will allow me to have just about anything.
You may also want to go the way of LEDs as they may be a bit pricey up front you save in the long run do to low electric bill, life of lighting surpasses this of T 5HO and Metal Halides.