If the radiator and primary fan are adequate and the engine is not extreme, you can probably dispense with the pusher fans. You might at least hold off on buying and installing them until you have the car built and sorted out. (Make sure the wiring harness for them is in place during build; that will save a ton of effort later.)
If you follow all the rules about the radiator, thermostat (don't forget to drill bleed holes) etc. you will likely not have any cooling problems. And, of course, be sure the block is thoroughly boiled and cleaned before assembly... a deep blockage in the water jacket can cause lifetime problems.
The
oil cooler is
de rigueur for originality, but it can be a complete PITA any time you drive in cooler temps or for short drives. Mine has the remote
oil filter and cooler, and I have yet to get the
oil past 70* even on warmish days and long freeway drives. So my next project is to cut in a Canton oil thermostat - pics and details will be up when I'm finished. That will keep the cooler and at least one quart of oil out of the loop while it warms up and stays at 80* or higher, which is where the oil temp needs to reside for proper lubrication and boiling out water and other volatiles that don't belong there. I would have removed the cooler entirely if it didn't routinely exceed 100* here through the summer; I suspect I will need the cooling capacity for longer summer drives.