Wooden Canopy For 48"x18" Tank

So I'm entertaining the idea of doing a canopy for our 90 gallon that we'll be setting up soon. I currently have a 4 piece glass top for it.
My options for a top right now are to use my tops that I have for my 55 gallon and a add a piece of glass on each side to close it off, thus meaning I would be using two 18" T8 lights.
Next option would be to use two LED strips I currently have on another tank + the 4 piece glass I already have.
Last option (reason of post) is to build a canopy out of wood, that would have a flip open front and I could hand my fancy pants LED lighting system I recently bought used lol. That light is meant to be hung and is about 36"x10". (QUESTION I'm curious as to how far above the water line it would need to be to have the best coverage?

I like this look of canopy I found via Pintrest:


The light I have looks like this:


More than likely, I would paint it black, since the stand I have for he 90 gallon suffered some water damage from the previous owner, so I would want to paint it black as well...

Thanks in advanced!

 

Also forgot to ask. How much breathing would it require? Can I have it as tight as possible or should I have holes or gaps in it?

 

Usually the back of the canopy is open. So there is some breathing through the back. If you need more then there is no reason you couldn't put vents in the top or even install computer fans in the top to cool the surface.

I am in the planning stages of a canopy for my 75 gallon actually and have a slightly different plan in mind. I'll try to take pics of the canopy on my 40 gallon to show you.

Basically I try to avoid the canopies where the top is the entry point. Makes water changes much more difficult. I also like canopies where the front ridge is as short as possible as to not give the entry point any more elevation.

 

I love that canopy example you posted, it would work perfectly with the above-tank sump I would need to incorporate. I've been planning one out myself for down the road, so following this!

 

Here's what I have for our bigger tank.
I didn't build it, but I was part of the build haha

 

Decided to try something quick to see how my light would work. I'll try it with the light higher, but right now I don't like the fact that the T-Bar is making a big shadow lol