Very low wiper resistance Digital Pots - Anyone know of any?
You will likely not find such a part because there will always be some kind of electrical switch in a digital potentiometer, and these always have some built-in resistance.

You can however compensate the resistance. You've already linked one article that shows it, but you can improve upon that.

A single OpAmp and three resistors can work as a negative resistor. If you tune the negative resistance to your wiper resistance you end up with near perfect compensation. 

Wikipedia Article on Negative Impendance Converters 

For your application there is even a article on the web that does exactly what you need: 

Negative Resistance Nulls Potentiometer's Wiper Resistance