Since that train ride between 18:45 and 10:40 there is little point in Sleeper Class (SL) to take, it is most of the dark ride. Do you have the money, take good 1AC, the most luxurious class, compared with flying too expensive. Have you ever seen Trains From Lucknow? From Lucknow to Varanasi, I recommend as the 4266 Class Sleeper treinfan Dehradun Varanasi Express (8.00 – 18.25). That’s ten hours, and an entire sitting. At the end of the ride you can assess whether the rest of your trip by the SL, 2AC or 3AC be it wants to.