Magento gift set product

Hi, I need a gift set type of product developed. It has to allow me to set the price, quantity ...etc, of the SET, rather than individual products in the set. then when the order is placed, the order will have to contain all products in the set, so the quantity of each product will decrease by the quantity ordered in the order. Also, as the gift set that contains multiple products are likely to be 10 or 15% off the total price, the order flowing back to the back end has to contain each product with their original price and a sale price. Thanks