The difference is of tyre size, where 16-inch wheels come with tyres that have larger sidewalls that act as cushions against sharp edges on the roads, like ruts and potholes. While 17-inch tyres look much better, provides a better grip on the road and no doubt increases the car ground clearance too.
For the availability, 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.
