I checked Z1, but couldnt find a NA 5spd transmission. I did find their conversion package. Ovbiously, you would only need the transmission. But that runs for 1825$ If you are only looking for the transmission, the cost would be less. And its a used transmission. Here is the link:
http://www.z1motorsports.com/p...=1877
If you were looking for a brand new 5 spd, they offer the 98 jspec transmission for 1795$. Here is the link:
http://www.z1motorsports.com/p...=1684
I havent checked other website, but you should check them before purchasing. I know that Z1 charges a bit more, so I would look to the other websites before spending, you may save a few bucks.
Have you checked the classified section?
Hope this helps.