Add product name and amount to contacts or potential

Add product name and amount to contacts or potential

We are online retailing products with Zoho as our CRM.

We have a huge number of product we sell and we would like to be able to filter out customers by SKUs, product name, total amount of their purchases.

We see that we are able to add products but we are not able to add the quantity, and also we could not add the same product twice. we have different variations of the same product and would also like to track it.

Is there a way to go about this?

Also, I would like to report Customer lifetime value, or simply the amount each contacts have bought according to the amount in potential. Is there a way to easily do this?

Thanks