if you really own our discontinued "Melodyne plugin", then you only have the 32-bit option. 64-bit versions were introduced with Melodyne singletrack (aka. editor, assistant, or essential) Version 1.2, if I remember correctly. There is only one installer for both versions.
I'm having some problems with Soundscape, small sections of tracks works to transfere and tune OK but not sections as long as the whole track.
We have not tested Melodyne with Soundscape (please see here
). But if you give us more details, we can at least check if this is a DAW-related problem. See also here
for some general advice as well as some info about what we need for a proper bug report.