Large Tank Filtration

We're a long way from our new fishroom, but have started gearing up for the filtration system.

Purchased a Clarity CL-3 which the vendor is holding for me until we need it.
http://www.koienterprise.com/Clarity-Protein-Skimmers-sc-546.html

It's going to be running off a 330 gallon sump fed by two external overflow boxes. The overflow boxes are 48"L x 6"W x 18" deep. One of the Ultimas will also be plumbed into the sump. There are 12 holes drilled into the top of the tank for 1.5" pipe. Main mechanical filtration will be 4 large spa filters run by two ReeFlo Hammerhead pumps. Because the fishroom has yet to be built (DIY), there will be plumbing--drains, water, and electrical outlets where they are needed. We're one engineering report away from getting our building permit. The filtration room is triangular-shaped and will be full. We think we can get the old 300 gallon tank in there, too....don't know what we'll do with it, but we can probably find some use for it.

Thanks! We're going to need it now that the building addition is a DIY affair. They're threatening to ship the tank (which I purchased late August) anytime. They've been gracious in delaying the shipping this long. When it arrives, it will be placed on a flatbed trailer by forklift. The trailer and tank will go into a large storage unit, until we have a place for the tank. The whole process started in August, and we still don't have the building permit in hand. Not to mention that it could rain every day until May. We're going to have to work around the rain. This is hard for an impatient person.

Thanks for your kind thoughts. It's appreciated.