Try Mcmaster Carr.
I went to their site and did a search on "foot switch". Lots of choices.
I saw one (under light duty, die-cast zinc) that was two pedals interlocked so that only one switch could be closed at a time. Sounds like it would work. http://www.mcmaster.com/
Not sure about the speed control, hmmm.
[This message has been edited by Amazingmg (edited 12-23-2005).]