One of the most important decisions that you have to make for sous vide cooking is which immersion circulator to get. Now, for the most part, any immersion circulator will perform the same role. This focuses on heating the water and circulating it through the container. As a result, you will get good food, regardless of the specific immersion circulator you choose.
However, there are many different models to choose from and there can be significant differences between them. This does mean that some options are going to be a better choice for your situation than others.