You can try Severscheck. They have several different models that support SNMP. Their website is https://serverscheck.com. They also have pricing on their site which is very convenient.
At my last job, we purchased an PDU with networking and a temperature sensor option. I think it was an APC. We needed the extra PDU connections, but gained the ability to monitor the temperature sensor and power draw on the PDU via SNMP. We only got one sensor each for our main and secondary data centers, then I was able to build a temp chart for the NOC with both temp sensors on one chart.
We use Minigoose watchdogs, and we took them out because solarwinds kept alerting us that they were rebooting every 4 hours. It got old quick. But if i remember i was able to pull in data... i think.
