For the availability of Hyundai Verna 2019 model, we would suggest you walk into the nearest dealership as they will be the better person to assist you because it depends on their stock book. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Car Showrooms
Well, both the variants have the same engine and delivers the same power its just about the features. SX(O) has more features than SX. SX (O) comes with features like side and curtain airbag, sunroof, electronic stability control, hill start assist, front parking sensors, tyre pressure monitoring system, R16 Diamond cut alloys, leather seat upholstery, Hyundai BlueLink Connected Car tech and front ventilated seats, etc. So if you are planning for a fully-loaded car then you can choose to go with SX (O) variant else you can choose SX variant. Moreover, for a complete comparison, you can click on the following link - Comparision.