There are several issues that should be examined before you can make an informed decision.
1. B visa or ESTA does not allow you to “work:”
To enter the USA, a B-1 visa or ESTA (Visa Waiver Program) is a good option, but you need to remember, these visas do not allow you to actually engage in income generating business yourself. There are several impediments to what you can do. You are, of course, allowed to enter the USA, seek a business, negotiate and/or purchase the business. You are also allowed to incorporate and/or start a new business, including, a US branch of your business in your home country.
Read about B (the same limitations exist for ESTA entries) visas: http://www.immigration.com/visa/b-visa/b-visa-overview
2. Are you already a part of or own an established business in your home country?
(a) Yes: Look at the following options:
i. L-1 (Intra-company transferee – visas where you have or are starting a company related to your foreign company) http://www.immigration.com/visa/l-visa/l-visa-overview
ii. E-1 and E-2 (Treaty trader and treaty investor visas – require a treaty between your home country and the USA. India does not have any such treaties with the USA. http://www.immigration.com/visa/e-visa/e-visa-overview
iii. EB-5 (These are investment-based green cards requiring investment of $500,000 or $1 Million and creation/preservation of ten American jobs over two years) http://www.immigration.com/greencard/eb5-green-card/eb-5-investment-green-card
(b) No: Look at E-1/E-2 and EB-5 visas (links are in the previous para).
3. Should you convert from B visa to any other visa?
Generally speaking, that is a bad idea. Watch this video: http://youtu.be/es4SlhcXr9E
For more information related to B visas, you can watch videos from this play list: https://www.youtube.com/playlist?list=PL13184E6EA97A1593
4. How do you start a business in the USA:
This matter should be addressed based upon the advice you receive from legal counsel in the State where you wish to start your business. The incorporation of foreign business entities is regulated at the state level (as opposed to the federal or national level) in the United States. The application process will vary from state-to-state. Here is a good resource page from SBA, Small Business Administration (SBA is a US Government agency) on the types of business entities you can form in the USA. Generally speaking, you, as a B or ESTA visitor, should be able to form any of these entities: http://www.sba.gov/category/navigation-structure/starting-managing-business/starting-business/choose-your-business-stru