This type of options based pricing is not a feature of eCart so it would be a completely custom implementation. In order to help you get things going I will need very specific requirements when it comes to how you would like the prices to be determined based on the selections. Knowing and understanding the specific criteria that will be involved in the pricing is key. If this criteria has not yet been determined you will need to review the overall requirements and determine how you would like the pricing to be applied based on the selections of the user.
I assume you talking about the hosting when you mention India, any host that is accessible from the internet should work, however it may be difficult to contact support or resolve problems with your host if any occur.