A standard "Sequence Dart" would probably fit your needs under two conditions: 1) you have relative high-capicty on the pump feed (a 2" feed is required for the Dart) and 2) you have relative low head pressure for the return. The Sequence Dart is very energy efficient but only in low load conditions. In other words, it is a good water mover, but it is certainly not a presssure-rated pump by any means.
For high-head applications, a pressure-rated pump such as the Iwaki series or Panworld may be more appropriate, but then it'll cost you on the energy consumption end