I have two businesses; a marketing firm and a real estate firm.  I'd like to include both firms contacts and accounts in Zoho CRM. 

What's the best way to classify and sort them?  If I classify contacts and accounts by "industry", can I sort by "industry"?
Or do I need to classify them by a custom field such as "Product type"?  Can I sort by that custom field?

Suggestions?

Herb H