professional (programs selling) website (php support)

We search for the best bid (price and quality) to design a professional website with wonderfull interface , to buy from it our program products . Some of our programs are attached , If the coder have experience , it is better to show us previous websites he designed . the coder should make us able to edit this web site easily to add future designed programs web pages . the interface should be wonderfull professional look , and in the same time supported to be browsed by the most browsers