We need to integrate QuickBook with our website to manage accounting. When someone register at our website, a customer should be created in QuickBook
and after succesful order, it should be avilable in QB.
Apply only if you have good experience with QuickBook API and WHMCS for managing invoice/billing to my customers
This would be an easy way if you consider to Quickbooks API which is released by ConsoliByte as well. The API is a free license so you could use it for either commercial or private purpose.