I am looking into building a new tank 72 x 30 x 25 (LxWxH) what kind of over flows would be best? center or corner? Or what options do I have?

Coast to coast Calfo style is what I would do.

+1
coast to coast calfo style is what i would do.

Doesn't have to be coast-to-coast, just big enough for three holes for 1" bulkheads. Bring the return(s) over the back. That falls in the "if I had to do it again" category for me... I'd probably put the overflow along the back in one corner, and put the return over the back in the corner on the other side.