
Prior to this meeting I had read some information about the two proposed forms of business but
still had some doubts, hence we went to visit his CA.

This meeting again proved is important to do your homework... I could understand everything thanks to what I had learnt in the morning.
Either partnership firm or sole proprietorship have the same unstable or shaky or at least non-corporate look to other companies, while a private limited looks more reliable to your possible clients.
However, the difference in costs is quite significant. The upfront cost to set up a Private Ltd is at least Rs.15,000 to 20,000 (very minimum); for a partnership firm is about Rs.8,000; finally, for a sole proprietorship is nil: you just need to go to the bank and open your account in the company's name.
This is, as you can read here, because the sole Proprietorship depends directly on its owner, both for liability as well as taxes; in fact, the company and its owner are one. The same way, it is very similar for a partnership firm but the profits and liability is distributed among the partners.
Our conclusion is that for a business which is beginning and a large amount of investments has already been done, you should go for the Sole Proprietorship or Partnership Firm. But if you have time and money is better to go for Pvt. Ltd. as it will give a much more reliable outlook to your enterprise.
Update on 23-02-11: Would you like to see the Spanish translation? Click here!
Update on 23-02-11: Would you like to see the Spanish translation? Click here!