Initial capital in a private company

Dear Sir/madam,

I am planning to start a new company. The company will be a internet based online company.

I read about LLP vs Private limited in this forum and since most ppl suggest for a private limited I am thinking to go for a private limited.

I am currently investing around 2 laks for software development of the website and later over the period of 1 year I might spend more than a lakh over advertisement and other running costs.

What do you suggest to quote me as the initial Capital.

I thought of putting 2 lakhs so I pay less fees while I start the company.

Is there any other advantage if I put extra initial capital so I can cover the running cost for an year( for example if my turnover for the first year is 15 laks the first 5 lakhs of my turnover will be considered as investment so I don't need to pay tax)

Also let me know whether getting digital signature is mandatory.

I am not sure whether I am totally naïve regarding the questions.