Checkout Page Integrated Into Current Design

I want a checkout page added into my design. My entire site is written in HTML and CSS. I would like to use HTML and CSS for the checkout page, but if what I want demands more than HTML I am open to it. THE CHECKOUT PAGE MUST: Be a one page checkout, Tie into [login to view URL] API do process CC instantly, Tie into PayPal so that after successful payment it directs them back to thank you page, Must work with SSL Have the capability to add/remove products and add on upgrades during checkout, Email me every time an order is placed. Email customer with receipt and order number after successful payment, Have a successful payment page, that they will only be redirected to if the payment goes through, MUST BE PROFESSIONAL LOOKING, THIS IS FOR A COMPANY. NO CHEESY LOOKING LAYOUT'S. I ALREADY HAVE: [login to view URL] Merchant Account, PayPal Business Account, SSL Installed. This is for a service company, there are only 8 different products that can be bought, but I want to be able to have them choose add-ons inside the checkout page. I need this done ASAP, I know that someone who knows what they are doing or has done this before should be able to complete this in 1 to 3 days. YOU MUST RESPOND TO ME QUICKLY OR I WILL IGNORE YOUR BID, I NEED DEDICATED PEOPLE!