Well I did a demo for our local reef club tonight on tank drilling. I have some pics so I will post up a photo thread when I get time (the holidays are really keeping me busy and to top it off I am changing jobs within the next week). Keep your eyes out for it. Also I would personally take returns over the top of the tank as it is easier to drill siphon breaks in them that way. I'm not sure how the manufacturers like AGA deal with siphon breaks when they bring the returns up the overflows I'd have to check one out to be sure.