e-commerce website customerization

I need a e-commerce website. I do not want start from scratch rather buy one on the web but I need someone to customize it for me. There are tons of company offering complete e-commerce package or web-based POS,Inventory software which have similar functions and prices. You have to choose one that you think you are comfortable to work with. I need extras that they are usually not offering: 1, Video Clip: A employee at back-end could easily manipulate video clip as following: Erase any part at two clicks.(start and end points to erase) Put watermark (automatic) Input letters, Combine sound track, Bookmark video with database items(Suppliers, products etc.)( By choose from database or Add new Items to database). Those bookmarks are searchable and invisible to website visitor. Those video clip are reside on website server for sometime(active) and then move to another site(achieved) and still linked to website. At Frontend a visitor can open a video clip at a custom media player window which has buttons like PLAY, FAST FORWARD, FAST BACKWARD, PAUSE. A CAPTURE button will capture a picture frame in separate windows with a pointer, visitor can drag this pointer to specific location of the picture and add some comments in comments field and click SEND button to send a request (contains picture with pointer and comments) to backend. 2, At Frontend I need several plugins: a, Cost calculation: when visitor input a money amount, website will automatically add tax and shipping and handling cost and convert this amount to local currency where customer reside. b, Price inquiry: When customer input a product first search by own site and then search web using 1-2 search and compare engine like [login to view URL] or pricegrabber.com. c, Payment integration: Need collect payment in several countries and each of them has different system. 3, Design website template: I want you design 2 template one for main page(homepage) and another one for rest pages. Do not copy templates from web, I want you make it from scratch so they are unique and no security risk(others' template may contain backdoor where my site can be hacked) Please respond with following: Cost of the software you are going to work on.(like Magento,Prostores,- I will pay) Cost of other plug ins which can be purchased(I will pay) Proven experience on video software and website design. A copy/paste generic reply will be rejected.