Wagerworks provides software to some excellent operators but some of their affi programs indeed do not keep up with the high quality standards of the Casinos itself.
In regards to Paddy Power’s program, I can provide you with the email address of relevant people, but suggest to check out http://www.paddypartners.com first. 
As far as GetMinted goes, you can contact them @ [email protected].
I am unable to answer your question about the US part however, as I am based in Euroland.