[rgulrich]

Hey Kevin,
You might consider the C2C or somesuch, but external - keeping the plumbing to the corners as much as possible to minimize their visual impact. That said...(drum roll)....

I'd be almost tempted to do an internal Herbie with the intake and emergency both integrated into your oyster reef structure, preferably at two different areas of the aquarium. The return could be over the top in a corner, or again, integrated into your aquascape (a bit tougher). Remember - you will need to access this plumbing in case of an emergency or blockage or somesuch, so you don't want to tuck it back in a corner somewhere under the Euro-bracing. You also need to provide support to the entire bottom of your acrylic aquarium, so you'd have to be very judicious in your use of a hole cutter (to fit bulkheads and tighten/loosen them) in the wood supporting the bottom.

Sit down, preferably with a cold beverage of your choice and a pad of paper and pencil, and do some sketches. You know what you want to see and support in your aquarium, now "all" you have to do is develop the means to support it in an aesthetically pleasing manner. Be sure to review the sketches in a day or two to make sure you didn't leave anything out.

You're doing all of this already, so I don't think you'll have too many problems getting there from here, man.