I don't know what kind of availability there is but if you use CAPS to look up the part number, you can get a price in JNZs OEM catalog. All of the different cars (gvr4, FWD DSM, AWD DSM) seem to work interchangeably but have different part numbers. On some sets, both cables are adjustable, and on others, only one is adjustable. So your best bet might be to just call JNZ and ask them about it - they're pretty knowledgable.
As far as install, it seems like a PITA but it's easy. Just pull the center console, pull out the pins and clips at both ends, get the two bolts on the firewall from inside the car, and the one on the block that holds them down under the dash. The least annoying method I've found for reaching the two bolts is to get in on the driver's side, and lay across both front seats.