cable spec: differential characteristic impedance
You don't want the 6365 Alphawire for the connection: while there are 5 twisted pairs, the pairs are not shielded individually. You might have unwanted interference. Better use Belden 9842, 120-Ohms. But it has common shield.
If 1-pair cable, it has 120 Ohms in one shield.. 

For RS-422 (100 Ohm) there is Belden 8162, with individually-shielded pairs. 

I am sure if you search deeper, you will find 120-Ohm individually-shielded  multi-conductor cable.

CORRECTION: since the RS-485 is supposed to be completely balanced, the cross-talk is very diminished, which allows to use non-individually shielded twisted pairs. The classic cable for two full-duplex links is Belden 3109A, pictured in TI guide.