Sound Module


OK, I am totally ignorant when it comes to this stuff as you'll figure out by my questions below. But, could someone just send me on the right path to start?

What are the machines called that are rectangular, a bit bigger than a computer screen and they have black rectangular pads on them? It's like what Neil Peart uses on Spirit of Radio. Are they expensive? How useful are they for a rock band? I would like to sample in maybe some Bell gongs and use it to play Spirit of the Radio. Where can you get the sounds?