Isolation on outputs
The most common solution for your problem is to use an isolation amplifier such as Analog Devices AD210.  Note that there are many different models available from many suppliers.

Isolation amplifiers are generally broken into two categories: 2-port &amp; 3-port.  The number of ports specifies how many isolated sections are in the amplifier.  A 3-port isolation amplifier has the input separated from the output with both sections separated from the power supply input.  A 2-port isolation amplifier has the power supply in the same section as either the input or output, depending on that particular model.  Obviously, 2-port isloation amplifiers cost less than 3-port units.

Also be aware that the isolation voltage is different between ports.  The AD210 that I mentioned earlier has higher isolation voltage rating between the input port and both other ports whereas the output port has a lower isolation voltage between itself and the power supply port.

A quick Google search for the search terms "isolation amplifier" will show you the plethora of options available.

Note also that I as speaking of Analog isolation amplifiers.  If you have the ability to convert a digital bitstream into your desired result at the destination, there exists another plethora of digital isolation devices.