How to Customize CRM to have People (Non-Leads being Pursued on Multichannel), Leads (People w/ a Need or Interest), and Clients? C

How to Customize CRM to have People (Non-Leads being Pursued on Multichannel), Leads (People w/ a Need or Interest), and Clients? C

I am building out the CRM for a small retail leasing company in NYC and anyone who owns a building or a business with retail space is my market. Half of our sales tasks are spent turning them into leads. If successful they sign an exclusive and become a listing client or they start searching for space with us.
I am using the Enterprise Edition during the Zoho One evaluation period.
The current Leads to Contacts relationship doesn't work for us at all.
Apparently the only possible conversion is from Lead to Contact as it is now.
As an aside, "Contact" seems like a poor choice of Module Name when a large part of implementation is migrating all of our "Contacts" into Zoho CRM. Client works for me since there is generally 1 decision maker.
How do I build a module for all my Non-Lead Contacts (People). This should be able to populate the Lead module once a need or interest has been identified.
Can I "convert" other than simply changing and customizing the "Lead" module which can convert to a "Contact (Client)" Module?
Can a non-lead Person stay a Person and also be a Lead which then converts to "Contact(Client)"?
Can this be customized further?
I am grateful for the help.