1.) I guess you confuse something here. There is only one 4-pin aquabus cable available. If you mean the high flow sensor (without USB/aquabus), it is using a 3-pin cable which is incompatible to the aquabus because of a different pin-layout and another plug on one end.
2.) There is no cable necessary. A sensor is already integrated to the mps.
Thanks Shoggy but then what is the "TEMP" port on the MPS for? I thought another cable had to be run from that to the AQ5?