Very few canon P&S can take much over 1FPS still photos continuously. You can look the Canon specs to find out what shooting rate a camera supports, CHDK does not change this. CHDK does not have the capability to record video at non-standard framerates, so you can't do say 2 fps HD video to get what you want.
Generally, shooting stills at lower resolution does not increase shooting rate, but a few models have a specific reduced resolution mode that is faster. Some low light/high ISO modes also do this.
If you really need > 1FPS this should limit your search substantially.
Any CHDK supported camera can take timelapse using a script.