Homeseer has a zwave leak sensor with a long lead. Monoprice zwave contact sensors have an external connector built in as well. I use them for a dry contact for cell phone chargers.
I'm using a Fibaro FGBS-222 Smart Implant. I've got a Nortel phone system in the house, but my mom doesn't hear it ringing when her TV is on. I've wired the dry ring contacts on the phone system to the implant, which when the phone is ringing, turns on a HUE light in her room under the TV. This Fibaro device has various inputs/outputs for different functions.
You might be able to use DWZWAVE2.5-ECO, I bought mine on amazon. When you take the cover offer, you can hardwire two leads to it. I'm using it with my smoke detectors to send an alert if the alarm is sounding.
I'm using the DWZWAVE2.5-ECO as well. Thanks to a lot of help from this forum, I'm using it to monitor a septic alarm. Nice device, with a screw terminal built right in.
I didnt yet. Partly cause I'v ebeen busy and not working on my home automation stuff.
But mostly, I think $40 is a bit much for something that might NEVER alert ever. I will wait for my Konnected.io device and just wire it in for the cost of some old speaker wire I have laying around.