Hey Doug,
For functionality I would love to have the false wall cap be taller but esthetics (AKA my fiance) are (is) winning the battle on the tank design - hence the reason for doing everything I can to hide the equipment as much as possible. *Ouch! That whip stings!*
When I discussed setting up the tank with my fiance she became interested and loved the idea with the caveat that it not look like a science experiment and that it look more like a piece of furniture/art work. So she started looking with me on discussion boards for tank designs that she liked. She liked the contemporary look of the open top frameless tanks and Japanese style tanks. For example she liked this person's tank but didn't like the wires on the wall from the suspended lights (therefore I'm compromising by using a less obtrusive Coralife Aqualight Pro Clip-on 150W HQI) and she didn't like seeing the plumbing in the overflow boxes (therefore I'm building a cap over the false wall):
After looking into options today I think I'll likely end up having to run a JBJ ATO to keep up with the evaporation, but the up side is that the tank will require less daily maintenance for me.