Well, I re-thought things and decided that having my return plumbing go right through the back wall posed a risk of overflowing my sump. Even with a syphon break, the water pressure in the tank would still drain a fair amount of water.
Because my return plumbing is now going up and over the back wall, there wasn't really a benefit to closing it all in the way that I had originally planned.
Here are some sketches I did:
I plan on having black acrylic on the back wall to prevent the overflow and plumbing from being visible.
- Chad