I've read all of these threads on a PID and I find my electronics knowledge to be apparently just short of what I need to fully understand all of it.
I was looking on Ebay; is this kit the kind of thing that would work?
http://www.ebay.com/itm/PID-REX-C100...item19f33b057b
I think I'd need a different thermocouple, but the price for the other two pieces seems remarkably cheap. They can be had from many different locations.