This came up just a bit ago. The problem is the weight of 3 feet of water. You will have to brace the heck of your wood sides. Someone suggested an above ground swimming pool. They are made to support themselves. At least you are putting it on a slab so you dont have to worry about the floor.
As for the light. Depends on if you want plants or not. If plants then you will need a bunch of lights, do a search aquarium lighting. If no plants then you only need enough to see your fish. Do provide a timer for the lights so they fish dont spend too much time in the dark.
yankee dog
