Hey Joe Mama!
In order to run four or more pads, you would need a third party software with MIDI controller capabilities (see manual p. 33). The Mandala Virtual Brain (VB) can run up to 3 pads.
I don't know what Danny uses in his rack. However, you can clearly see Battery 3 running on his laptop that triggers his seven pads. http://www.youtube.com/watch?v=Rx9oU1CF7HA
The Mandala manual illustrates possible set-ups and dependent on your budget, your sickness mileage may vary.