There are various chip manufacturers who can supply power metering chips that are easily implemented and low cost. The electronics distributor Digikey is the best place to start. The various offerings that they carry can be reviewed at this link: http://www.digikey.com/product-sear...ng/2556716
Since you are using the CR3110-3000 split core, your circuitry will need to compensate for the phase error that comes from using a split core device. These methods are discussed within many of the data sheets for the power metering chips found above.