MSI packages allow an unattended install with the addition of a /qn to the install line.
>msiexec C:\Path\To\InstallPackage.msi /qn
In SolarWinds MSP, there are a couple of script options for installing:
(This can be done in a Monitoring Template if you have a lot of machines on which to distribute)
Go to the Tasks Tab of the machine you want to install software
Click on the "+" To add automated task.
Scroll down to Install/Remove Software
Select the Install type you want and hit <next>
<fill out as needed>
Don't forget to select the  Run File check box
The operators for different installers go directly in the Run Parameters. They are different for different installer software. A good reference can be found here: