Build a Website

Hello. I already have a website, but it needs to be completed and optimized. For example, 1. Existing products, images, and data need to be updated or corrected. 2. New products (approximately 800) need to be added, including images and all pricing and sku, manufacturer, shipping, etc data needs to be added. 3. Automatic shipping calculation needs to take place using FedEx, UPS, etc. 4. Need to be able to accept credit cards (I have an existing merchant account) and Paypal.