I originally made it when the tank was a reef tank. I had metal halids and VHO lights mounted in them. Mine does not use doors on top or on the front. I made a separate frame that wraps on the tanks edge. Then the canopy sits on top of that and the whole canopy lifts up so I can essentially lean over the whole tank as if there was no canopy for easy access. Its not real pretty I never stained it. I had 5" fans mounted on each sides on the front to suck out the hot air created by my Metal Halids. Right now there removed so I just have these big round holes on each side which I use as port holes to feed the fish through without lifting up the canopy.
Here I have halve lifted up. Its propped up with a 6" piece of wood. I also have a 12" piece of wood if I need it lifted higher for catching fish.