Yamnotri - Gangotri - Tapovan - Advise/Cost

Dear Friends,
Hi to everybody, I just register myself today & starting this thread.

We 3-4 friends from office are planning for small trekking to Gomukh & Tapovan by mid of Aug (13th Aug specifically). We are going by own vehicle. Need advise on below points for this trip.

1. Any major risk for our trip during this monsoon period (Although rain god is not happy this time )
2. Pony/Porter need to be booked in advance or we can book in Gangotri, not mentioning utterkashi as we are going first to Yamnotri & then Gangotri.
3. How many porter will be required.
4. Average Cost of 1 pony & 1 porter.
5. How/where to get permits for trekking & cost.
6. How to arrange accomodation/food during trekking. Cost for the same.
7. Things we should carry along with us.

And your Experienced advices for the trip. Please answer friends.

I think Vikram answered your question on the other thread. PLEASE DO NOT POST the same question under more than one thread.

Thank you for your understanding.