Hi! I'm a new QB member and I live in India. I may be able to help a bit...
Where in India will you be working? Singer/Merit and Usha/Janome are the two big sewing machine companies, and both have a pretty good presence all over India, even in the smaller towns. Especially with the treadle machines, you should be able to find someone who can service them/find parts...
As for sewing kits, you can find reputable brands of scissors and needles in the larger cities - fiskars and pony are popular. Same with pins, tape measures etc. for under $5/person, you should be able to make up a pretty decent kit.
Best wishes for a successful trip.