Hi
Our Real Estate Manager for create sites with propertiers
ordasoft.com/Real-Estate-Manager-Software-Joomla.html - is OpenSource component. If you know HTML/CSS/PHP - you may change there all
Now we in Real Estate Manager have only CSV and XML import/export
If you need JSON
We may propose to you order this as "customization service".
Please write to OrdaSoft contact form (
ordasoft.com/contact-us-form) with full details description, how all must look and work, and we will give to you quota.
Best Regards,
OrdaSoft team