The latest version (1.11) is available from Corel's website, and this has a single executable.  You can extract the 32 and 64 bit installers from this by running the following:

CorelPDFFusion.exe /extract_all <pathname>

Once extracted, you should see a 32-bit and a 64-bit installer.  To deploy silently, use the following command:

CorelPDFFusionInstaller_x86.exe /s /v/qn /v"SERIALNUMBER=AAAA-BBBB-CCCC-DDDD" /v"ASSOCIATE_PDF_XPS=0"

(putting your serial number in instead of AAAA-BBBB-CCCC-DDDD)

the 64 bit installer is CorelPDFFusionInstaller_x64.exe with the same command line.

Use a capital V for msiexec commands:

CorelPDFFusionInstaller_x86.exe /s /v/qn /V"SERIALNUMBER=AAAA-BBBB-CCCC-DDDD" /v"ASSOCIATE_PDF_XPS=0"