Need help for Sikkim Trip in early April'16


New Member

We (5 friends) are planning for a trip to Sikkim + Darjeeling from Bangalore during 6th April - 10th April 2016.
One of our friend is staying in Bhubaneshwar.
We (from bangalore) are thinking to go via flight to Kolkata on 6th April (probably first flight) and meet our friend (from bhubaneshwar, he will come there by train) there and then hire a taxi for our trip.
Or should we select some other city airport to meet together and then go via taxi or train on the trip.

We would like to cover as many places as possible there in this short trip.

Also, let us know if some permit is required we need to carry some additional documents?

Regarding hotels (mid-range), if you could suggest us, whether to do advance booking or would it be easy to find hotels there on reaching.

During this trip, if we keep traveling at night so that we get full day to see the places...would it be fine?

Please suggest and help us with an itinerary for this trip.