the big question i have it wat kind of tank will this be? comunity fish and sps tank or soofties/lps tank? alot depends on what you want to house in the tank. then you need to match the equiptment to those animals and bio load.
lighting
sump
reactor
skimmer
water flow pumps
computer system
water change tanks
water storage tanks
ro/di systems
these are the items that you will need to size to the bio load of the tank.
this will be an awesome system once it is finished. there is only a couple of tanks that are close to the size of the ank you want to build here on reef central.
here is some good reading for you on a big tank.
http://archive.reefcentral.com/forum...hreadid=861003