Temperature Controller Confusion

I searched the threads and read a bit on the topic buy I still have a noobish question for the experts out there. I am trying to build a side by side kegerator/fermentation chamber out of an old fridge as inspired by these:
https://www.homebrewtalk.com/f51/side-side-kegerator-fermentation-chamber-161176/
https://www.homebrewtalk.com/f51/fridgenstein-side-side-kegerator-fermentation-chamber-289241/
And several others on this site.
I have almost everything taken care of with the exception of the taps and the temperature controller/s. I am assuming that I should by a single stage and a dual stage temperature controller. I would hook the single stage up to the freezer cooling unit and the probe would obviously be in the freezer side. Then I would use the Dual stage in the Fridge side because I would need to attach it to the damper switch to cool and a heat source for heat. Right?

I ask because I recall reading that someone said to use the single for the fridge and the dual for the freezer which didn't make sense to me. I have read a few threads about it but never found a simple yes or no answer... Any and all advice is welcome. Thanks in advance!

This is the fridge in its current state:

I would just buy two stc-1000's and you'll be good to go.

do you have two separate cooling circuits in there? most side-by-sides only have one refrigerant system to cool the freezer, then when the fridge needs cooling, it pipes cold air in from the freezer (essentially). just FYI... it might not be as simple as getting two temp controllers and wiring them up as two completely separate systems.

audger said:

do you have two separate cooling circuits in there? most side-by-sides only have one refrigerant system to cool the freezer, then when the fridge needs cooling, it pipes cold air in from the freezer (essentially). just FYI... it might not be as simple as getting two temp controllers and wiring them up as two completely separate systems.

Click to expand...

It should be exactly that simple. (I think). You are right, there should be only one cooling system for the freezer and the fridge uses a damper/fan to draw cool air in from the freezer side. So as I said in the OP I would hook up the single relay temp controller to the freezer to maintain a regular serving temp (38-40 degrees F) and I would use the dual stage (2 relay) temp controller to control the damper (cool air in from freezer) and what ever heat source I figure out. At least this is my understanding of how it should be done. Hence this thread which I created to make sure I was seeing things the right way. Now wiring this whole thing up may be a completely different story... Maybe I will have to start a new thread to get help figuring that out!