REGA Speaker cable

I have a MIRA and Celestion SL6 non-biwired book shelf speakers. I would like to connect them with REGA speaker cable. Due to poor logistics, each run will be 20 feet. Both REGA's SC42 and Quattro are 4-wire cables, although the Quattro can be separated into 2-wire runs.

1) Suggestion on a configuration? For example, it was suggested I take the Quattro and run 2 wires into each terminal, or I could split the cable into 2 separate cable runs. I have also seen that the SC42 is the better cable for long runs.

2) I have not been able to locate in the US a place to buy SC42, although I have found a place that has the Quattro. Any one know where I can buy the SC42?

Any thoughts would be much appreciated - thank you.