Lost my mind....or, here we go again!

[Delphinus]

External overflow unless you need the tank up against the wall. I HATE how much real estate my internal overflow eats up out of my 280g.

Center overflow, or coast to coast. (External or internal, either way). That way if you go wavebox the wave will be minimized at the overflow and sloshing is minimized.

Leave enough space over top of the overflow. Especially if you go with a non centered overflow and you have a wavebox.

I think Herbie > Durso. Durso really only good for reducing gurgling noise. Herbie is quieter and makes microbubbles pretty much impossible since there is no way for air to enter the plumbing. Well, except for the skimmer anyhow and anything else, but at least the overflow intake is submerged completely so it can't draw in air.

There's another kind of overflow system whose name I can't remember but it's basically Herbie extreme. You need 3 holes for it. That might be something to look into.