Date Difference,
To work with a Compact Vision System you will need either
1. LV Vision Dev. Module
2. LabVIEW Real time module
3. LabVIEW Professional or Full Development system
or
1. Vision builder for Automated Inspection
Yes you can uses two systems at the same time. You can programmatically have LabVIEW communicate across the ethernet, or any of the serial ports. The communication can be between the CVSs or any other machines.