Welcome to ZUKIWORLD.
I have just gone through a big headache with my speedo setup. In my area,(southern Colorado), Advanced auto(western auto), and NAPA have cables, besides the zuki dealer. They are cheaper than from Suzuki, but they are too long!!!! What a PITA! The first one I bought broke in a few miles because it kinked when I got it cluster put back in. So I had to buy another. Then I find out that NAPA sells one for a little cheaper(about $25, compared to $27). Then I call the Suzuki Dealer, and theirs was about $43. Lets see 27*2=$52, plus time spent messing with it, and now it has some wobble at lower speeds. I think that the Genuine part would be well worth it. The tranny to the firewall is VERY easy. The rest is the hard part. Make sure the cable comes under the far left air vent before it hooks to the cluster. I went over it to take up some slack, but that is where the kink came from I think. You can go and search my speedo problems on this board to see all my troubles with the dang thing.
Glad to be fo some help
Jeff
PS, where are you located?