So Current Ideas, (I have a Few.)
Idea 1 is this, and its really not my preferable Idea, as its heavy and a PAIN in the rear to do it.
In that idea, there is a PVC sheet as a Floor, 2 PVC sheets as Walls on the outside, and 4 dividers throughout the center. I will build a 3 inch, Substrate dam out of PVC, and screen doors will fit inside of the PVC.
So it will look something like this.
The Unit will be 45 inches wide, 18 (and change) inches tall, and 12 inches deep. Each cell will be 9" w (about) 18" tall (About) 12" deep.
The Material list, you see above will build 2 units (10 cells) with a Ton of Screen Frame left over, and some Extra PVC, that is waste (I surely could find a use for it HA!) So 2 more, doubles everything but the frame. Obviously there is still hardware not listed, like hinges and door latches but those should not cost that much.
My Concerns with this method.
Weight! This will be fairly heavy, that 1/2 inch PVC foamboard is defiantly not featherlite. Its not super heavy, but its not light either. A fix for that, is to use a similar to old DS design, and build screen cages and then mount them together, with PVC sheets between them, this would WAY reduce the cost, and slightly reduce the work, and may be an option to consider. However! I am not sure what the cost would be, and merging the Units I am not sure how to do. (Something I may still look into)
IDEA 2.
Another option I had seen, before was the "Rubbermaid All Access" method. There use to be a Bin by Rubbermaid, that has a plastic clear door, and was a bin pretty much as normal other than that. I have found a TON of "Shoeboxs" like it, however not one that is sized correctly, except 1.
The one I seen, was a double shoebox/Boot/Sweater, it was 9 inches tall, 18 inches wide, and 14 inches deep. However, the door opened bottom up, or top down, so If I stacked those on their sides, they would be 9"w x 14"d x 18" tall, PERFECT. I would just have to cut the top out and add a screen from and glue them together and boom done. Sadly they were on Amazon UK, and "Currently Unavailable"
There is HOPE! Someone else in the world, has to make a bin like that. If I can find it, I can build IT! It would be stupid easy, STUPID CHEAP (the bins were 8 a piece!) and for the less DIY inclined or me if being lazy, you could drill some front vents in the door, and drill some holes for the 4 inch round vents in the roof. (A rectangle with frame would be better though).
That would be the HOLY GRAIL, of Chameleon Baby caging!