The main feature of ClassicWB P96 is that it has Picasso 96 installed and supports compatible video boards.
I use 800x600 at 60 Hz in 24-bit color, but I think it can go up to 1344x1080. Enable "Picasso 96 support" in the hardware options and give it some Zorro III RAM, and add the lines "window_width=800" and "window_height=600", or whatever resolution you prefer, in the custom configuration, and boot up and check the Workbench screen-mode preferences.
Games and older programs that use the native Amiga modes may look a bit weird, and you will have to play around with the viewport settings to make them resize and fit nicely in the new larger window.