Hello, I am part of India based company, and can collect the required data for you. As per my understanding you basically need 400 contact details (i.e. company name, company representative, mail and postal address, contact no.). Apart from the categories of companies you mentioned, we can also go for these to sell composting dry toilets.
1. Indian Institutes of Technologies/Managements (as there are generally more than 10k students, 20-30 hostels and other residential areas in which faculty used to live in each institute, and they constantly improve way of living, so they order everything in mass, and one institute follows other .... )
2. we can collect data of the NGO, that motivates new technologies in india, and can advertize your product at no cost, if you could convince them about product.
3. Companies that offer modular furnishing, kitchen etc.
4. Companies which sell green products and new technology innovations in India.
As you can see till now my 5 star rating, and 100 percent completion rate.
Waiting for a positive reply
Thanks :)
I updated the bid for collecting 400 contacts and emailing them your letter