Online Shop Modification.

I want to modify my e-store : I'm currently using zencart, but I don't mind switching to other opensource shopping cart like magento / prestashop as long as I can handle the back end. Basically I want the following features: 1. Quantity discount with "Add to Cart" on each option like this: [login to view URL] 2. "Buy together and save" like amazon and the website listed above too. 3. Recommended products page appear when customer adds item to cart 4. Wholesale status / wholesale pricing only for registered users 5. Slideshow banner on homepage. 6. Facebook and Twitter icon on site header that link to our fb and twitter page. 7. Facebook like button on every product we sell 8. Live chat ability 9. A section where customers can download our catalog (which we will provide as PDF file) in a single click. 10. Customer upload file capability just like here: [login to view URL] Notice that they require a customer number to ensure the file goes to the right account. Please tell me that you will be able to do this too. If not, please suggest an alternative solution. Basically I want customers to have the ability to upload their file online and I'll receive them. In terms of appearance, I want it to be as close to amazon as possible. The look, the feel, the ease of use. I don't want it to look 100% or even 90% the same design tho. I hope you get what I mean. I also would like to have a big drop down menu that shows all sub and subsub categories like this: [login to view URL] (by the way this is something you can download and use for free -- I don't know if that will be useful for you..hmmm) or [login to view URL] or [login to view URL] (just hover over the top menu) The purpose of this is so visitors can access a product at the least click possible. So all the do is hover on the menu and all the sub and subsub comes out. I do not need any graphically interesting pictures for my site. I just want a clean cut, easy to read (not too big / small text). The color combination is red, black, and white for the whole template. Another very important thing is the top part of the site have to be simple and effective. Referring back to [login to view URL] The header has to be 150 pixel height the most and should consist: company logo, facebook and twitter icon, a live chat button, a search bar that is not tiny, and a shopping cart link. You do not have to design a company logo for me as I already have one and I can provide in any size you need. I'm not a web designer or developer in any way. I have been working so hard to get my site to look like how it is right now and there are still so many things I want to add to it, I just can't push my brain any further. So, please help me. If you have any further question please contact me. Thank you so much! JM.S.