With the familiar looking Integrated Development Environment of Lizajet Studio you can define exactly the Installation you want, and extend it with event handlers using the Editor.

When you can work with Delphi, you can work with LizaJet Installer

Just like in Delphi you can create Dialogs with the layout you prefer, set properties and create event handlers written in Object Pascal Script for each of the components you place on the Dialog.
You can associate forms with Installation Actions, and define event handlers for each of the Actions; just like it is done in Delphi.
On each moment you can switch to code view, edit the event handlers directly with the Script Editor and debug it with the Script Debugger.

You can work with your usual components, click on them and see the properties and events.