External overflow through a bulkhead?

[Myka]

Anyone using a bulkhead to provide flow for an external overflow? I'm trying to figure out a way to do an external Herbie overflow on my nano, but want to avoid the bulk of an internal overflow box. I don't have the ability to grind a long U shape in the back pane of the tank for an overflow, so I'm looking at ways to get the water out with bulkheads. I'm only looking at about 150-200 gph through the overflow.

My first idea is a single 1" bulkhead through the tank with a basket strainer on it. This goes into an external overflow box with two standpipes for the Herbie. The basket on the bulkhead in the tank will be 1-2" below the water surface with the Herbie controlling the water level in the overflow box which when plumbed this way will match the water level in the tank itself. I'm not sure I like this idea.

My second idea is two 3/4" bulkheads through the tank with basket strainers. No overflow box at all. These would be plumbed with a gate valve on one to control water level as per Herbie, and the other would be the emergency drain. This would require 90 degree elbows in the tank otherwise the water level would end up being too low since I can only drill so close to the top of the glass. I'm not too keen on having gaudy white elbows in the tank, but this seems like a much safer idea.

My third idea is to find out how much the glass company would scam me for to grind out a U-shaped section for a perdy "pro" external overflow. Hmm...sounds expensive, and risky for the tank.

Anyone have a better idea?