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[Bloodasp]

Looks like a better idea than the one you originally had. Not that the one was bad I just think this one would be a better way to go.
Probably use glass panels siliconed into your tank.
one thing im seeing though is that the water level will drop pretty much to the length of the lowest pipe. And if you are trying to build that original setup you were interested in that would mean a lot of water going into your sump.
What would be good would be to add a glass in between the overflow and the return pipe which would be as high as where you want your water level to be.