Requirements/Solution

My guess is that the best way to achieve the above is to simply get a normal domestic/commercial freezer and change the controller so that one can set temperatures as high as -2c...-5c etc. This should cause the chicken to freeze slowly and spend a lot of time between -2.2c and -5c. Perhaps I also need a function to be added which allows the temperature to fluctuate between -2 to -4c so that I can get the recrystalization. Initially this is just a proof of concept so I want it to be as cheap as possible so long as it fulfils the requirements. The requirements would be:

1. Any cheap freezer which would be suitable
2. Freezer must be able to set temperatures to -2c to -18c. Freezer will normally operate at -5c.
3. Freezer sensors set up should be decent as temperature is important factor.
4. Ideally a digital thermostat which also shows actual temp accurately, preferably real time.
5. Freezer would have roughly 100 litres capacity.
6. Initially I'll just put 1kg chicken in to see it works, however if it does work, I'd like to be able to support 6kg of chicken since I'd expect a 100 litre freezer to do that. Any case this is proof of concept so testing 2kg initially is fine.
7. It should be easy to modify later so that the fluctuating cycle e.g. -2c to -4c can be incorporated. I imagine that this can be achieved provided it is frost free since there is a fan in the freezer or via installation of a heater.