The main thing to look at when choosing a grow box is the space it offers you. Before you go out buying, remember to measure the exact living space a certain plant needs. If you don’t have a fully-grown plant yet, get that information from elsewhere, search for it on the internet, or ask someone that knows.
After you know the size of the box you need, check the ventilation system of each model. The airflow in a tent is an important factor because this will let you control the humidity and temperature levels that you have in the box. A good ventilation system will help you keep the environment inside in the best condition.
Although you might be tempted to also consider how much you spend for a grow box, a cheap grow box is not worth it if you are going to sell some or most of the yields you produce. It’s better if you spend more on a quality box.