How to capture a customer's address into CRM at the time of invoice and payment? (Paypal)

How to capture a customer's address into CRM at the time of invoice and payment? (Paypal)

I plan to use ZOHO CRM and ZOHO Invoice to handle sales for a custom computer business, but here is an important issue for me:

During the pre-sales stage, we create lead/contact for a potential customer. and we do not ask for the customer's address information at this stage. Our business is highly personalized in nature, and we communicate with the customers back and forth to discuss sales detail. We might use the "estimate" feature during this phase too. Once a final deal is reached, we create an invoice for the customer via Paypal.

Apparently, the billing/shipping address will be handled by Paypal itself.  But the thing is, we do want to store this information in ZOHO CRM as well for obvious record keeping and future marketing reasons. So my question is, is there a way for us to capture and insert the customer's address into the ZOHO CRM "contact" module in one smooth flow, without the need to manually insert this information into the CRM?

We can certainly make a web form to request this information, but the problem is how will this integrate with the invoice/payment feature? 

Your advice will be greatly appreciated!