Bulkhead and Overflow Size/Placement

Im looking to order either a 240 gallon (96x24x25) or 180 gallon (72x24x25) tank, depending on one measurement i have to check, and i was wondering what people recomend for the amount, size, and placement of the bulkheads and overflows.  Is it better to have more then one overflow, say one in each corner and one in the center each with one bulkhead?  Or is it better to have one large overflow in the center with 3 bulkheads?  Will 3 1.5" bulkheads be enough for either the 180 or 240 gallon tank to feed a 55 gallon fuge and appropriate sized sump?

when you have the return in the same overflow as the out, do you run PVC up to the top from the return or something?  how do you avoid the water that was just filtered getting sucked back down instead of pushing it out to the tank?  ive seen some where the return gets pushed out the side of the overflow, but that would require another hole to be drilled.

 

also would 2 sets of 1.5" bulkheads be enough for a 180-240 gallon tank?

Edited by DandT40