all this information makes a very big difference.
This is actually exactly what I do.
I would avoid paypal and the fees they charge.
Your better off going with a processing company

You should contact me at

I could give you several ideas or you could give my contact information to the group

Avoid storing credit cards information, unless and untill its the only way to go. There are some Payment Gateway services, if you want to accept payments in USD then check out PayPal for INR check out ICICI Bank, HDFC Bank, some other private players.