You don't need it but you can use it.You don't need a 7500 kelvin light, sunlight is either 6000k or 6500k
Also it looks like it's not gonna cover much area with light..
I don't know if it was mentioned but the aqueon clip ons are better. Also are you doing open top or lid tank. The tank model will decide which light you can get because some lights are not compatible with some tanks so I still think you should choose the tank model first.
personally for small tanks I reccomend this or something similar to this here
From the reviews it looks fine.
Lid. She has a betta. We're working on the tank
Cool light, A little pricy but looks ok.
Agreed7500 or 8000K is just fine, you can even grow plants with 10,000K.