Most grains are convenient to cook with sous vide, both because it makes it easy to replicate your results but also for the lack of cleanup required. I usually cook the grains in 1-pint or 1-quart Mason jars, depending on how much I need. I'll often leave the grains in the jars, chill them in cold water, and refrigerate them for later use. You can also mix and match grains, as long as they get done at about the same time.
The cooking time will depend entirely on the type of grain, but in general, it takes about 20% longer than is called for on the stove. The amount of liquid needed is also dependent on the grain, but is usually about 80% of what you usually need due to the lack of evaporation. I have used the below recipe on quinoa, farro, bulgur wheat and several others with great success.
Preheat a water bath to 183°F (83.9°C).
Combine the grains, water, and salt in a pint Mason jar. Hand tighten the lid, making sure not to over tighten it. Shake up the Mason jar then carefully place it in the water bath. Cook the grains for 20 to 60 minutes, until the water is absorbed and the grains are cooked through. Remove from the Mason jar and fluff with a fork before serving.