This is similar to what I'm doing. I have defined all of my features in InstallShield and I have an ini file that contains a value for each feature indicating whether it should be installed.
I've written a script function to read the ini file using the GetProfInt function when the installation starts and set a bunch of properties in my installation. Then I've set install conditions for the features that change the install level based on the properties that I've set, thus turning off and not installting the features that I don't want. You may be able to set the install level to 0 to hide a feature completely.
However I have a problem - which I've just created a post for - in that I can't get it to work with silent installations.
