I got the Powertec and it was a dud. I tried contacting Powertec twice to see if there was something I could do with it and they wouldn't even return my email to tell me to piss off. I tried every possible combination to make it work and even finally took it apart to see if something could be done. It would energize the circuit as long as I held the paddle down but would stop as soon as I released it. The magnet that was supposed to hold it down wasn't working. I'm not alone, reviews indicate that there is a small but predictable failure rate. Amazon refunded the money for the switch but not the $7-8 shipping charges. I recommend you buy one where you can walk in and return it for that reason.
As for a switch and where to mount it I went to a standard light switch in a dust proof enclosure, i.e. a plastic electrical box and that special cover. I mounted it on top of the plenum I built in my fence for dust control. Since I like to work from both sides of my table it couldn't be mounted on one side under the table. Since mounting it on the fence I've decided that I will never again mount one anywhere else. In my opinion this is the best and safest place you can put it.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.