May I suggest you check out Commercient's integration app. They have implemented over 85 integrations between multiple ERP & CRM's Including Quickbooks Online. Their integrations are highly customizable and can be as in-depth or as simple as needed. The app is also available on SugarExchange.
For integrating SugarCRM CE 6.5 with QuickBooks Online, you can explore tools like Skyvia for no-code integration or Zapier for basic workflows. They sync data like accounts and invoices. For more advanced needs, custom-built connectors or middleware might be required.
