start by downloading the installer files from here http://www.sketchup.com/download
Then create the SCCM package from the downloaded MSI file where the command line will look like this :
msiexec.exe /q ALLUSERS=2 /m MSIDSLXC /i "SketchUpPro-en.msi"
NOTE: I had to add /NORESTART at the end to prevent the client from rebooting after the installation.
Setup Type: Windows Installer (MSI)
Deployment Method Used: Windows Installer Command Line (No MST)