Not knowing where to get one of these (lots sold online, though I am in a rush to get started), I located AAAPrice, where I purchased an Infinity Foot Control IN-USB-2. The fellow who helped me there, Adam, not only gave me directions to their Brooklyn office (they usually sell online, so going to the office is a bit unusual. As I said, I was really in a rush to get this!), but he also showed me how to set it up with the basic (free!) software that works with these pedals, Express Scribe. He even gave me a printed set of instructions! I cannot recommend his company enough for the wonderful and personal service I received.
With this said, now off to transcribe!