Honda Shine 125

Since you are already used to the Honda Shine, we suggest that you try out your new commute on this same bike and then take a call after about a week of doing so, once your body has gotten accustomed to this longer ride. 
If you feel that you want something different, you can write back to us with what aspects of the ride you are unhappy with, and we can then recommend some bikes based on your budget

The 125cc commuter bike class is divided broadly into two groups - the traditional-looking, straightforward options and the sporty-looking, feature-loaded options. If you want something that's a 'typical' commuter bike, the Honda Shine 125, Hero Super Splendor 125 or Glamour models will fit the bill. On the other hand, if you want a commuter that has some flair to its styling and more features, the TVS Raider and Hero Xtreme 125R would be our recommendation. Both come with a single-seat option since that is something you've mentioned is a requirement for you.