Hi Josh
I look at them all and ended up using the PIR from these guy for several reasons but mainly as the alerts are instant. I have tried TXT ones but they can have a delay. The New PIR's have a sensitivity option and can eliminate false alarms. my outside PIR can trigger my wemo or I have a kumoapp that beep another tag. so I place the tag next to my bed, and it beeps when someone walks to my front door during the night.
I have been using a PIR KumoSensor and other sensor tags outdoors by heat sealing them in small plastic bags.