I don't know what ipens are.
The Hitachi projector you listed appears to just be a standard short throw projector. So, it will work with any interactive white board you purchase, but the projector itself contains no smart interactivity whatsoever.
If you want a interactive whiteboard or a interactive pen, you would need both the specific software and hardware which would be associated with those devices.
I have installed StarBoard products in the past and they have worked very well, but it is a completely separate product which will work with any projector on the market as long as the PC connected to it has the proper software on board and is connected, via USB, to the StarBoard itself.https://www.starboard-solution.com/
- Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.