I would have recommended a func pad. They've been around for almost 10 years, and have great pads for $20. Sadly, their store seems down...and I think it's been at least a month, so maybe they're out of business.
Anything should do really. The Razer pad recommended should be fine, though I'm not sure what price it is. Just make sure that it's a hard mat, and not a soft cloth one. It really makes a world of difference. Been running with my funcpad for 5 years now (and my previous one before that for 4 years, which I passed onto a friend).
This was their site:
http://func.net/
That Ratpadz seems cheap. If it's a hard pad, go for it. It doesn't need to be the best of the best...I'm sure you'll see an appreciable difference regardless.