Hello Pink,
If you are 20 plus persons, I suggest you rent Toyota Coaster (29 seater mini bus) . It costs Rs. 6000 to 8000 per 24 hours and plus Rs. 18-25 per km for fuel.
For hotel/guest houses I suggest you search at the net, you should be prepared to pay Rs. 6000 to 10,000 per room of accomodation.