If you want to punt top level US pornstars you will need a big bank balance. They start at $1000 and there's no limit to how high they can go from there. Julia Ann doesn't seem to be available but there was a rumour she was once charging $10,000 or more.
You'll absolutely need to be verified to punt in America so pay Roomservice2000 a visit, pay $50 and give them a lot of personal information (where you live, where you work etc) then book a flight and a nice hotel in Los Angeles as most of the pornstars don't seem to tour here anymore. Make contact with a few agencies when you are out there like Pamela Peaks Talent, The Luxury Companion, Lourdes Enterprise, Photogirls etc and have a great but extremely expensive time.
On the other hand there are a handful or relatively well known pornstars that may be touring with UK agencies. Photogirls for instance has Franceska Jaimes, Bridgette B, Janine Lindemulder, Mellanie Monroe, Jill Kelly & Shay Fox among others. Eitherway it'll cost you
