Controlling lagering temp for multiple carboys

Just scored a used chest freezer for $50, just big enough for lagering (2) 6.5g carboys.

I'm wondering if anybody has suggestions on which Temperature Controller and where to order it from?

I also thought about picking up the stopper thermowell http://www.northernbrewer.com/temp-control.html

but I'm not sure if the capillary for other controllers will fit in it.
Anybody ever used it with other controllers?

W/ 2 different carboys, is it safe to use a stopper in one carboy and assume the other will be the same?

I would recommend a digital ranco temp controller. Very accurate and you can set the degree range very easily. I've heard the temp probe won't fit in the thermowells though. Good alternative is to tape the probe between the carboy and a piece of bubble wrap to the side of the carboy.

If you're fermenting beers that you've pitched at the same time, you can assume the internal temp will be about the same. If you are conditioning one that fermented out last week and adding a newly pitched one, I'd move the temp prove over to the new one because that one will create its own heat. I'd rather condition/age a beer a little cooler than primary ferment one hot.