Well I was able to get ahold of the tank manufacturer, dutch aquarium systems. Very nice gentlemen to chat with and very knowledgeable about the tank. He is confident that those filters are enough to sustain the tank. They have four black foam spools that are extremely efficient at filtration. Apparently he only recommends a pump running about 600-700 gph with it.
While he seems trustworthy I think I am still going to hook up one or maybe two FX5's to the tank.