For removing information directly from the computer keyboard, via local network, or automatically, the software version of the Terminator system is sufficient. You don't need a Terminator device; it's enough to download Terminator program and to purchase a software license.
This software version doesn't have any restrictions, delays or particularities; it is a complete system that supports all software methods of removing information.
To manage only the computer itself, you don't need WebElf device. Just download the Webelf program and buy an inexpensive software license.
In the software version, you can control power and restart of the computer, manipulate the local network and other Windows functions with standard program macros via mobile phone.
You don't need a Defender device to protect your premises from wiretapping if low level of security suits you fine. Just download the Defender program and purchase an inexpensive software license.
In the software version you'll be using standard office computer speakers to protect your premises from reading.