D1&D2 coaches have seating arrangement same as SL(3per Berth) , so you can enjoy SL in 2S fare.
You can't get proper lunch in this but snacks/fruits are available almost every time.
For 16853 in Ms VM section they will sell tea ,water bottle and some snacks, only few vendors will be there . At VM they will sell samosa,vada,cool drinks ,milk and lunch (sambar Rice/biriyani/curd Rice/chappathi&kuruma). Once the train crosses PRTY the train will be filled with unauthorized vendors who will sell Guava fruit, Jackfruit, Salted cashew, Groundnuts,Veg soup. you can...
more... find at least 20 Guava fruit seller in this train , one authorized vendor will sell lunch and vada (he comes rarely).
For 16854 same applies till VM and from VM they will sea tea &snacks . If you start the travel from your home it is advisable carry Lunch.
Punctuality Tip: will get delayed at all intermediate station but will reach the final station on time or with neglible delay(most of the days)