What is your actual question?
CNC4PC's C76 web page is messed up, so I can't see the specs or a manual., but I'd assume it would have analog spindle speed control, that should work for either one.
If the VFD's are genuine Huanyang VFD's, then there's a Huanuang plugin that works very well.
The Amazon VFD looks legit, but the Ebay one looks like a knockoff copy.