I have no experience with the Beckett pumps. For 5.00, I would get the 5000. You can always throttle down the returns with ball valves. I think you are going to have to do that anyway. I would put a ball-valve before each tank. you may need that level of control when fine tunning the return. Remember, to take into consideration that the max head pressure will be affected by all the returns in the way. Even though you have it going to the top first your top row has a drop-oof the moment the water gets there. Water will want to find the lowest level always.
I personally wouldn't tackle your project with on pump. I would give the top row its own pump and the remaining tanks another pumps. There are several benefits to this as you can obviously imagine. I am working on a similar project and I am looking to learn from you. I am working on a display set-up like your that will go into a LFS. Two things, I am terrified of PVC overflows (so I will be drilling the back of my tanks (either acrylic or plywood)) and I will use multiple pumps. A little more cost but operationally less risky. The set up I am making is only two rows, each row is eight feet long (4 to 5 tanks per row).
The pumps that I referring to are the Danner Mag pumps. Google it they are sold everywhere and at least in my neck of the world (Miami, Fl.), they are the pump of choice.
Frankly, your project is exciting and is providing us with a lot of information. I appreciate you sharing with us.