While MRF Zapper Q is a pretty good tyre and you can go ahead with it, yet I would suggest that you buy it in stock size. This is because we do not recommend upsizing in case of 2 wheelers as it hampers the riding and handling characteristics of the vehicle. Only Bajaj people could tell you if you should upsize or not.
Other options would be MRF Zapper FY1 for the front and MRF Zapper Y for rear.
Sachin Pawarvia Google
Which one is Best Suited Rear tyre for CB Twister ?