The "thermostat" is just a box that you plug the slow cooker into and then plug the unit into the outlet. Reducing the amount of power reduces the temp. There are hundreds of DIY sous vide setups on the web.
I simply can't see taking the TMX out of action for such an extended period of time when there are other items that need to be processed or cooked. Even with the way I use it, which is not near as much as most on this forum do, I want it ready to go when I need it and quickly cleaned and ready to do something else.
The minimum time to cook chicken, cut into serving pieces, is 63 minutes at 165 degrees F. Denser meats take much longer.
This site has a lot of general information.
Frankly, I've been served foods cooked sous vide and they just don't appeal to me. Perhaps it is because I like more "rustic" foods but I like the texture and flavor of foods cooked in traditional ways. But that's just my opinion.
I was offered a Sous Vide Supreme and much as I like gadgets and appliances, turned it down because I don't want it.