I assume you mean in-wall duplex outlet with metering. Honestly, the only Z-Wave model I've found that included metering is the Enerwave ZW15RM, and it's a new product that I doubt many people have a this point. The cost about $50 with shipping, but the only retailer currently selling them (topgreener.com) doesn't list them online, so you have call them. Also, I've never seen an in-wall Zigbee device that did metering.
If you find any other in-wall duplex outlets with metering, please list them, I'm struggling to find any besides the Enerwave.