Yes you may have big business and osCommerce may not provide few function which meet to your business. But we can customize osCommerce to meet your requirements. Actually osCommerce is built to meet all general features of e-commerce. But for most advanced and specific to your special business process you need to customize some modules of osCommerce.
osCommerce supports all most al popular payment gateways but if you need to have payment processing with your preferred gateway (May be most popular in your country) and which is not supported by osCommerce then Just give as url of your payment gateway. Our expert team will research and give you quote.
osCommerce have shipping module which works based on quantity, weight and locations. Also osCommerce has modules which calculates live shipping rates from popular shipping companies like UPS, USPS, FedEx etc. But You might have special shipping calculation based on your product and business logic. Just give us your shipping logic we will create special shipping module for you.
Apart from Payment and shipping we can customize osCommerce to support special discount logics, droppshipping and country based customization (like Date formats for UK). Feel free to Contact Complete osCommerce Here for any type of customization or osCommerce modifications.