Embeddable widget of a Magento 1.9 store

Hi, We are looking for experts to build an Embeddable widget of a magento store with a multi vendors type. We allow vendors to sell virtual products in our magento store, those vendors have their own seller ID, and from their front profile they can publish new sellable virtual products and manage those items freely. Now we want to allow our vendors to copy an HTML code or script in form of <iframe>. to Paste it into their blog or website HTML in order to allow their visitors to make purchases directly from that embedded widget without going back to main store to complete the purchase. This mean that following steps: 1-Selecting items -->2-add to cart--> 3-Proceed to checkout--> 4-Register/login--> 5-Complete payment--> 6-Thank you page. All the above steps are happening within the widget. How the process should work? 1- We from magento admin side, "enable/disable" Embed Widget Option for our sellers manually, with a Yes/No attribute to be added to customer's admin profile. 2- One "Embed Widget" is enabled, Seller ID will have this option available in his front profile. 3- From there he could Generate, Customise some Colour styles and then Select the HTML code and copy it to his website. 4- The HTML code is connected to our Store via API, that will only display that Sellers items, and then embed those items to his widget.