It boils down to your lifestyle & your adaptability to intermittent fasting. It's usually not recommended for beginners to fast many hours by adopting windows like 16:8 and 17:7.
With any biological changes gradual is always way to go & also suddenly reducing eat time may diacourage your desire for the fasting
Also, does your lifestyle permit prolonged fasting like sleep&wake time? For effifacy 16 hours may be better since it also allows more time for tummy to prep for night's sleep