It is backwards compatible. One kit gives the drive power, while the other hacks the drive's PCB and send out the info through SATA cable.
It might not be compatible for 83850c v2/93450c drives. Unless you can connect it up somehow to the diygadget CK3 GND/5.0V solder pad (most likely they should remain unused but I am not sure). It doesn't matter since you have a 75850c drive.
Looks like you can simply ignore the solder pads/paints on the diygadget CK3 kit and then connect it up to your computer, drive, and probe as normal (using the provided cables the came with the new kit).
The USB extractor driver shouldn't be hard to install if you know what you are doing, and along with JungleFlasher. It's a driver file meant for Vista/7. It might be because you have 64-bit Windows, and not 32-bit. I am not sure if there are other alternate USB extractor drivers. If you have experience installing 32-bit drivers under 64-bit Windows, it shouldn't be too hard (
compatibility mode/UAC/DEP/digital driver signing/admin profile, etc). I guess you will have to use a Windows XP virtual machine if you have an incompatible operating system, or find a hack to force it to install. Also, I would recommend that all services/processes are started.
Here's a different tutorial -
http://www.megaupload.com/?d=IF91SN2M Don't attempt to proceed with the JungleFlasher tutorial until you are certain the drivers are installed.