Can anyone advise where I could source a 19" rack Gigabit POE panel with 12-16 ports and very important to have LAN control to switch off/on individual POE ports ?

I was looking into the same challenge recently. There's the Phihong POE370U which offers a network interface for managemengt (web interface) and snmp monitoring.
But looking at the pricing, a decent PoE switch might come in cheaper.

-Chris