I am looking to create a website like etsy and amazon.com

I am looking to create a website like etsy and amazon.com
Here is what I want my website to do.
1. the ability for users to make a account and post their items (with out having to create a store)
2. the ability to take a percentage or a flat fee ( I prefer a flat fee)
3. the ability to to check out like amazon.com where there is one shopping cart but splits the shipping if being shipped by two different sellers.
4. A theme like pinterest.

So far I have wp running with milti sites.
Frame market theme with marketpress.
Can any one help me achieve this ??
Plug-ins or themes I should be using as well as setting.
Thanks you