Design a high-end e-commerce

I am planning to start an e-commerce selling computer products, similar to www.cdw.com or www.tigerdirect.com.
I need to know what language(asp, php, jsp ??) and what database MYSQL, MS SQL, Oracle. Also how should I have hosted? Windows? Unix?

I can populate the with products from www.techdata.com but they don’t have the images in their upload files. How do I get all product info including images?
I appreciate your help.