Hello Taike
I have not played the EX2, however it uses a standard 3 GHz PC with 1 or more (Depending on specification) Creative Audigy Sound Cards, and so I would assume the sounds produced are Soundfonts.
Wersi do provide Pedal boards as extras, and come in with 13, 17 and 25 note versions. (All touch sensitive) They are however a little more expensive then off the shelf Midi Pedal boards, but they do not require a separate power supply. (They also have the standard Midi functions)

Bill