It's about 40" at the bottom of the transom and 42" in the middle bottom. I am not sure what I am going to have electrical wise but I figure it well all be mounted in the rear of the boat and the rear well be decked from the rear seat back to cover the gas tank, tool box, fire extinguisher ect. There should be more then enough room back there to mount a battery as well as a transom mounted trolling motor and fish finder. The front seat is being boxed in to make a storage area for the anchor and lines. The insides of the sides well be painted as well as the bow area and vertical supports for the seats, I am replacing the small aluminum seat supports with larger ones made from 1/2" ply. The tops of the seats, rear deck and the removable floor sections well be carpeted. Since I am dropping on my nice old SeaKing 12h.p. on the back I am replacing the transom plates with Oak and extending them further down the transom and I am going to make gussets to go between the transom and rear deck to provide even more support, should be pretty stout. Also all of the wood well be coated with marine epoxy because I have a bunch of it.
Anyway, that's the plan all spelled out, I need to get another sheet of ply for the floor, a 1x8 oak plank and some carpet and all the other assorted fasteners ect and that should be it.