Phone taping for sales training

In the past we have used a service to make randon sales calls that are taped for sales training purposes. We would like to go a step further and find a software/hardware ?
solution to actually tape the live/real sales prospects calling in. Does anyone have
a system(s) in place and how is it administered? We'll handle all the proper
notification of such procedures, just would like info on the systems that work?
solution to actually tape the live/real sales prospects calling in. Does anyone have
a system(s) in place and how is it administered? We'll handle all the proper
notification of such procedures, just would like info on the systems that work?