Do you have experience with eBay, Amazon, and Shopify?

Are you able to create an ecommerce website using Shopify, source products for resale and dropship from Amazon to eBay?
I am looking for a virtual assistant who can help with optimizing my online e-commerce store through Shopify and source products to sell on Shopify and eBay from Amazon. I am also looking for someone to fulfill orders from my eBay store using Amazon. I am also looking for someone who can help with customer service on my eBay store using eBay messages.