SecureIT

Hi, I'm looking to install x2 wireless hidden cameras which I will connect to my existing software on a PC. I need both these cameras to record colour video & audio simultaneously @ about 20-30fps each, in which the software is fully capable of doing. I also have a 4channel video/audio capture card. What I need to know is exactly how this works:: can I just use x1 Four Channel wireless receiver and tune each camera into it's own channel, or do I need x2 receivers?? Also do my cameras have to be multi channel as well?? Just to clarify: I need both feeds recording simultaneously so I can look back over footage as I need, NOT switch between cameras! Hope this makes sense =) thanks for looking.