why make one when you can buy one cheap. Fish only tank don't require much light. You can just buy any led lights. Even Home depot LED will work as long as it is above 7500K (daylight). Cheap ebay china lights will work too.
If budget is your concern than get home depot fluorescent light fixture and buy T5 from LFS.
Both of this option you can use a smart outlet to set timer and remote on/off.
I'm an electrician I have toyed with the idea of making my own led fixture. To be honest after the time spent gathering material and time spent assembling the fixture. The price difference is so small that's it's more practical to just buy an led fixture.
How big is the tank? I agree with the responses here....FOWLR does not require special lighting like maintaining coral. You would just want something that pleases your eyes. The Ocean Revive T247 is a great light (probably more than you require) but it is fairly cheap and has a built in timer, and you can control 2 channels, (all colors other than blue and blue...so it can act as a sunrise/sunset effect although it's only on/off sort of thing). It's about $160 per light and they can light approximately a 24"x24" area of the tank. You can even add coral later on if you choose to do so with that light.