I am looking into buying a stream kit for my 125g(6ft) reef. Don't know which one to get. Currently for flow I have a Gen X PCX40 as a return hooked up to Oceans Motions 2-way. The outlets are in each corner facing the middle of the tank. Also using several powerheads in random locations. Would like to take out the powerheads. I also have a 3inch sandbed. Was thinking of the TS21 kit. How should I positioned the pumps. As much as possible I am trying for an side to side motion.