I can tell you which one NOT to buy: "EEZTire" from Amazon.
I'm down to my last four operational senders. None of the six on the PC work anymore -- I just moved the last working one from the PC to replace one on the toad. The batteries are supposed to last years. In reality, I have to replace them about every other trip, but the sensors themselves have just quit working completely, one by one.
But I'm definitely a believer in TPMS. Without it, I probably would have towed my Smart to Florida with the brakes dragging, when my RVi2 brake failed. It set off the temperature alarm on the TPMS which was the only way I would have known there was a problem. As it was, that RVi2 brake still cost me a $700 brake job.