I'm currently building a custom Field Service Management solution within Creator and I'm trying to decide if I should use Zoho Books or my custom application for our Customer Portal. We are a lawn company and my customers need to be able to see all billing and service history records, as well as submit support tickets, update cc info, etc. 

Should I use Zoho Books and send the service data from our custom app? Or does it work the other way around and I need to send Zoho Books information to my custom app and use the customer portal with creator?

Thanks for any suggestions. I appreciate it. Chris