Rel sub cable options

I want to upgrade the neutrik cable on my Rel Storm III. Has anyone compared the Kimber Kable and Rel Blue cables? The Rel is almost twice as much (but also twice as long).
Signal...I have the Analysis plus one as well, but prefer the Signal cable.  
I just picked up a pair of S/510s that I'll be driving from PS Audio M1200 monoblocs.  I have some extra Kimber 8TC lying around and was planning on using a single run of each to each sub.  Using the Speakon 4-pole connector, I plan on using 8 conductors split in half for the 2 positive terminals and the other 8 conductors split in half for the 2 negative terminals; so there will be 4 individual conductors on each pole of the Speakon.

REL makes a big deal about talking about the resistance of the cable in concert with their input design.  Am I using too much wire and will it be a problem?  Almost everything I see for sale is only 2 conductors per pole.

Good idea?  Bad idea?  I already own all the pieces so there is no cost outlay.
After my post, I found the 'Russ Andrews' REL cable made from 8TC.  That is almost exactly what I'm going to do except.....where he has 2 leads for a right + channel and a left + channel, I'll combine the wires into one lead for a single + connection.  As I said, I'm using monoblocs.

So maybe I'm all set!? :-)
Signal Cable does not state what kind of solder it uses. I am wondering if it just regular and not pure silver solder as with the Rel Bassline Blue.