Good cheap pants to wear under suit

I'm going to be starting digitigrade padding soon, and I need some good, cheap pants to wear under the suit and to attach the padding to. I would like the best option for the smallest price.

Is this good?
http://www.dickssportinggoods.com/product/index.jsp?productId=11999631&cp=4406646.4413887.4414035.4414027.4413879.12181219

What about these?
http://www.dickssportinggoods.com/product/index.jsp?productId=21202916&cp=4406646.4413887.4414035.4414027.4413879.12181219

What do you use and where can I get it?
(I only went to the Dick's website because my friend works there and can get me a discount)