Planning a trip for someone to go from Kolkata to Darjeeling. I know the overnight trains all stop at NJP and you have to take either the toy train or the bus/car to Darjeeling. I want to know in terms of comfort which overnight train would be the best? I saw in terms of seat availablity the codes show 2A, 3A and SL. Could someone please elaborate what they are? I am keen on a sleeping berth in the best possible class with AC. The planned travel date is 11th of April so any advice early on would be a big help.