Recommended is TCS,
but due to unknown circumstances you might need to use 3rd part digital video recoders
Remember when you use DVRs you can capture far-end voice & video + near-end video (from splitting the HDMI cable) but this does not include near-end voice. Workaround would be to use other microphones connected directly to the DVR.
You may try the following site for external recoders.
http://www.epiphan.com/