There are three different Kimber Select products, specifically, all copper, copper/silver hybrid, and all-silver, and each is made as interconnects and speaker cables. Each sounds slightly different.
Because the performance of interconnects and speaker cables is heavily dependent upon their synergy with the other components in a system, the only comparison that matters is how each performs in your system (or in a system exactly identical to yours). To that end, buy both, break them in thoroughly so you know they are performing as intended, and keep the one that sounds best. To choose cabling any other way is gambling.
Because the performance of interconnects and speaker cables is heavily dependent upon their synergy with the other components in a system, the only comparison that matters is how each performs in your system (or in a system exactly identical to yours). To that end, buy both, break them in thoroughly so you know they are performing as intended, and keep the one that sounds best. To choose cabling any other way is gambling.