Dear Sir, This bid is only a PRE-BID. To bid correctly, I will need more info about your SAP B1 software, and a list of features you want to include.
We know Opencart very well, we have been created module with other ERP/CRM software, where people push products, clients etc to Opencart, but each solution can differ.
Please contact me with details and I will quote for you and if you choose us, we will deliver a quality product (VQMOD based solution, not alter your Opencart).
Regards, Valics Lehel