etech, from what I know of scripts out there, many people have't found them that great - you'd need to hire a programmer to build you custom code.
Otherwise, our Basic or Advanced Private Label System (new!) is probably the best offering currently you will find (in my humble opinion), however at this point it doesn't include the ability to private label our affiliate system (it may down the road).
It is built with ease of integration to existing affiliate systems though, so you could just purchase a 3rd-party affiliate system like NATS or MPA3 and use that for your affiliate part
Anyhow if interested to discuss, just hit me up or signup at
http://affiliates.iwantu.com 