Center Overflow - Size question

[Todd]

I am starting to plan out a new tank - my tank right now is against a wall, but I would like a tank that I would be able to use as a room divider, or a peninsula (one end against a wall, two sides and one end viewable); as I will be moving in the next year and would like options for future placements. The only way that I can think of that will let me have the tank fully plumbed (I was thinking 4 holes - 2 for overflow (herbie style), one for return, one for electrical wires to canopy) and be able to place it anywhere I would like in the future would be to have a center overflow.

So my question is this, what is the smallest sized tank that you would put a center overflow on, or have seen one on? How wide / long / tall, do you think the tank would have to be so the overflow would look okay and not stick out? Also, would a center overflow look bad if the tank was put against the wall?