I put together this thing last year before I got out of the brewing hobby. Here's a thread with pictures.
I'll sell the whole shebang for $350 (includes chest freezer with collar, ST-1000 temperature controller, a Sanke keg (dip tube removed), 50' of copper tubing, and 8' of Flex-Watt heater). It works in principle but would need some additional work to get it where it needs to go in terms of efficiency. Brazed copper, insulation, etc.
If I don't get any takers for the whole thing I'll part it out.