Dakota Digital makes both the sender: SEN-01-1 and the interface box: SGI-5. Total for both shows to be ~ $110.00 or so. I have both on my S10xGN truck and they work well to drive both a 2k pulse for the ECM and a 4k pulse for the truck speedo.
I figure the 200R4 was in cars long enough to get a really VSS generator at some point. I have a 4 pole inline I could use but a real VSS would be prefered.