Hallo Michael again,

when you have symmetrical signal routing you can use something like that:

http://www.analog.com/productSe..._492_b.pdf , figure 3.

Using such a topology you can transmit signals over extremely long cables. The best performance you will achieve, when filtering signal down to sinus. Drastical reducing of slew rate of output signal is allways of benefit, when transmitting signals over long distances. Otherwise careful matching to transmission line impedance would be necessary.
You need not to use shown transformer. But I would use a cable with common shield, with both ends connected to ground. Combined with shown protection (transzorbs), circuitry will withstand extremely high EMI.

Bye,
Kai