If you are looking APP-V 5 SP1 client MSI files, then stop looking. APP-V 5 client MSI files are inside the appv_client_setup.exe file.
To extract the MSI files you need to execute following command:
If you check the extracted files, then you will see appv_client_MSI_x86.msi and appv_client_MSI_x64.msi files.
References
How to Deploy the APP-V 5 Client – http://technet.microsoft.com/en-us/library/jj713460.aspx
Excellent, thank for this one!