If you want comfort while riding then go for BULLET 350 or else you can go for Classic 350. If you’re tall then definitely go for BULLET 350. All other specifications are the same. Important: Bullet 350 doesn’t have an electric start. Therefore you may find it hard to kick start Bullet sometimes.
Get the Royal Enfield Bullet 350, change the handlebar to the Electra handle-bar or a RD350 handlebar. You won’t regret it.
If you are around 5’8" in height or less, go for the Classic 350. Still awesome to ride.
More than which one of the two you get, ensure you take care of the bike, run it in properly, and the awesome feeling you get with the wind in your hair(wear a helmet!), you will enjoy both of them equally