Dance pad for XBox?

I gave my nephews/niece my old XBox when I upgraded to the 360 and I'd like to get them something fun for Christmas. I wanted to get them something that would spur not vegging on the couch so I think a DDR game would be great.

I was looking around at games and hardware and it seems the ultimix 4 would be a good title based on the notes (difficulty ranging from very easy to hard). I don't know however what would be a good dance pad to get.

Anyone have any insight on these things? I find several different makers and models out there but don't have any clue as to which would be a good bang for the buck purchase. Your help in making me a cool uncle will be much appreciated ;)

Any thoughts on this:

http://cgi.ebay.com/ws/eBayISAPI.dll...category=21188