Lotta questions... ok to start I have twin 7.4L 500HP Mercs carburated .. i want to go closed cooling..

.. should I get a half or a whole system?
.. does it matter how much horse you have to what size heat exchangers you need?
.. i possibly want to run rootz blowers in the future. . Should I get front or rear mount kits?


Im pretty sure ill think of more things to ask.. let me know if theres anything else i should post to help narrow down a choice..I appreciate the help