Discounts fuctions in Zen Cart need changes - php / mysql required

I will not reply to copy/paste advertisements. Real coders only please! NO PAYMENT GATEWAY, DESIGN OR SEO REQUIRED! PLEASE READ THE PROJECT DETAILS AND ANSWER THE QUESTIONS BELOW. CONTACT ME IF SOMETHING IS NOT CLEAR. Discounts in Zen Cart currently could set via SaleMaker as %. I want more than one discount to be shown. Other discounts are to be calculated. The item page screen to be done this way: [login to view URL] this is html / javascript, which should be copied into the item page. Click the radio-buttons to test. R-button on the item page Brand New should be clicked by default and amount after discount (this discount assigned in the admin SalesMaker as it works right now) should be shown 2nd in text-box (one after "$" sign). Price shown in 2nd text-box should be calculated the same way as it's done now: PRICE (from db) - X% (assigned in db). If any other than default r-button clicked, the amount in text-box should change to: PRICE - Y%, where Y = X + Z. The values of Z (discount increment) is to be hard-coded for each r-button shown. For example: 2nd r-button Z = Z + 3% 3rd r-button Z = Z + 6% 4th r-button Z = Z + 9% ..... 8th r-button Z = Z + 21% When user clicks on the ADD TO CART Button (I will call it differently), all the info from first page including last shown price should be shown on simplified Checkout screen (see moc-up: [login to view URL]). This is basic I need. I want you to price this part. After it will be done, I will add some features for extra money. Requested Information: 1. Are you able to communicate via SKYPE during day time in California? 2. How fast after project will be assigned it will be finished? 3. Do you feel comfortable dealing with the existing code? 4. Tell me about your Internet connection. Speed? Quality?