I believe they use Teleflex cables which are cheap. You can upgrade to a Morse cable which is much thicker for about $175. The Teleflexs are listed at Overtons and the like. http://www.skidim.com/
sells everything imaginable for inboard boats. In my own boat someone turned the bilge off and it drew water into the cable causing it to seize completely. I removed the cable and drilled a small hole at the stern end of the housing just infront of the nut, used an equivelent of a dremel to clean the hole out so the grease would flow (Have to be careful to not nick the cable), then tapped it out and intstalled a zerk fittiing. I forced grease in and got the cable moving. After working it for a little while, mounted in a vice, it freed up completely and I reinstalled it in the boat. Every so often I would add a few pumps of grease to keep it smooth. The type of grease is not so important but I always used marine grease just because I keep a grease gun for the boats.
If I was to buy a new cable I would still add a zerk fitting, as the cables should come with them in the first place.