You could have up to 3 separate sets of transmitter/receiver displays of any one 330ft RF product- as long as it has the 330ft RF, there is an "ABC" switch that will allow you to pair A to A, B to B, and C to C.
The 00380W at walmart will not allow you to do this. However, the 00754W3 will allow you to, as it has the 330ft RF chip and the "ABC" switch. It is a bit more expensive, but is also a nice little unit.
I hope that this helps you, let me know if you have any other ?'s