You should be able to use the /quiet or /qn options with msiexec to perform a silent install.
MSI packages export public properties, which you can set with the PROPERTY=value syntax on the end of the msiexec parameters.
For example, this command installs a package with no UI and no reboot, with a log and two properties:
msiexec /i c:\path\to\package.msi /quiet /qn /norestart /log c:\path\to\install.log PROPERTY1=value1 PROPERTY2=value2
You can read the options for msiexec by just running it with no options from Start -> Run.