Ads System Website *

i need a ad system, so i can buy and sell ads on websites or at oudoor advertising spots, via a website. a good exampl of what i want is [login to view URL] Please do not ask me for more info, i just want something like a clone of the website above, you send me what you can provide me, and i will tell if i am ok, you do not have to do all the functios that exists in the [login to view URL] just those that will allow me to run a sell/buy ads company online. the payment system will be from paypal, so you do not need to do any coding for this part thank you