Can a new Google Apps account work with an existing Zoho CRM?

Can a new Google Apps account work with an existing Zoho CRM?

Zoho tells me that in order to get Zoho CRM to work with Google Apps I will have to activate Zoho CRM from within Google Apps Marketplace.  But what about my existing Zoho CRM?  I have done a lot of customization work to create fields etc, and to import contacts, and I don't want to lose that.  Does that all go to waste?

I will also want to use Zoho CRM email Add-on.