The SCXI-1125 with the 1316 connector take provide isolated inputs to 1000VDC, ample for 480V RMS. If you need Power Quality Measurements, L3 Com Analytics has a nice toolset for making more than just metering measurements. See the attached datasheet of the PQ tools.
For sensors, you might consider LEM or some of the other names mentioned in the attached files.
Preston Johnsoon
Preston Johnson
Solutions Manager, Industrial IoT: Condition Monitoring and Predictive Analytics
cbt
512 431 2371
preston.johnson@cbtechinc