Well, life got in the way yesterday. I did manage to get the overflow box put together.
Today wouldnt allow me enough time to do the switchover to sump but I was able to get one big important thing done. I was able to get a few additional framing members into the bottom of my stand. I added some framing so that the 40 breeder sits 3 inches back from the 75 gallon. This will allow me to eliminate using 90 bends to get into my sump with drains and return piping.
Then I cut my plywood floor, shimmed and leveled it so that the sump tank sits perfectly.
I had some vinyl tiles laying around so I covered the plywood with vinyl flooring. I wont bore anyone with the framing pics but here is a pic of the finished floor ready for sump install next saturday. Meanwhile now that I know exactly where the sump will sit. I can measure and build all my piping during the week and be ready for install next weekend.