Is this an in wall build? Sounds like it is when you said one broad side is viewable from the office side.
If it is, I have always wanted to do an in wall river style tank. With overflow on the right and return on left, or vis versa. You could dial up/down the flow to suit the fish, and with the overflow on one side, you could sacrifice a little tank length but drill the drains in the bottom of the tank and do a single glass wall to create an overflow with no overhang to worry about.