You can rule out the Sota if you are wanting to kill bacteria. It is good forlymph pulsing and some pain relief but not really geared for killing microbes. The Mpulse will be the simplest to operate (no car batteries/MPM2)There is also a unit from Australia or NZ mentioned here that looks as good or better than the Mpulse but more $$$ too. The MPM2 will cover more area than the others as it has a hoop you can put around your whole body. You are right, tough choice.