Order calculator and checkout

I need a script that calculates the price for a copywriting company. It will need a dropdown to select from eBooks, articles, salewriting, etc etc, a box for the number of words needed, boxes for other infos such as topics of the articles. The dropdown items will be different prices per word that need to be easily changable. Ex: eBooks are $0.10 per word, articles are $0.01 per word. The box for number of words needed is to be multiplied by the price per word of the selected dropdown item. Ex: Someone orders 10,000 words and wants them in article format. The price would be $100. What the script needs to do is calculate the above, display the price, take the customer to PayPal checkout, then after they pay it sends me the info they entered into the order form to my email (I need to be able to add up to 20 emails for it to send to). ------------------------------------------------------------- I would also like to see pricing on a coupon system. I create a coupon that a customer inputs on the order/calculation page and it deducts the amount I specify, shows them the new price with what was deducted, then takes them to PayPal. It can be fairly simple. ***********Make your bid for everything BUT the coupon system and state in PM how much it would cost for the coupons and we will discuss from there.***********