OpenERP and Zoho are both fragmented modular systems that can be very confusing. Without knowing your industry and complete set of needs, have you considered NetSuite, Sage, MS Dynamics, Aptean or Epicor?

Aside from feature sets, implementation and ongoing support and training are critical elements to consider. The other big challenge is getting buy-in from the users.

Have you considered starting with an open source or semi-custom, previously developed product and having it customized to your needs?

If you would like more information, let's have a phone call so I can better understanding your specific needs and point you in the right direction.

Best regards,

Kevin McCarthy
www.KevinMcCarthy.com