You are going to be running your skimmer, 2 reactors, chiller and return from one pump. I don't think that Quite one is going to cut it. The 5000 is rated at 1400gph, but that is with nothing attached, with head height and plumbing you are going to be well below that I would guess alot closer to 1000gph, minus 300 for the chiller you are looking at only 700gph at the return. That is not including the skimmer which you are saying needs 700gph and then the reactors that probably need around 300-400. If I were you I would definitely run the skimmer separately