I am in the states having just done what you propose fellas so may be able to help.
OG3 is correct. No matter what license you have the most the FAA will give away now is a Private License (they don't call it a PPL and won't know what you are talking about if you say that).
The written tests are fairly easy (multiple choice)... go to
www.webexams.com and you can practice them for free (the actual questions) or buy the Gleim textbook. Go to
www.faa.gov where they have what is called the PTS (practical test standards)... this tells you everything that will be done on any checkride so you know what is expected of you.
The Commercial Single engine land ride includes performing several maneuvers Lazy 8's, Chandelles, 8's on pylons, steep turns, slow flight, stalls, soft/short field landings/ t-o's, etc.. the Oral is quite comprehensive usually too with my twin oral lasting for 3hrs and my single oral lasting for almost 4hrs.
Weather services is a lot different in the US then Australia (for one thing it's all free!!!... the FAA doesn't charge for anything). You will be quizzed indepth on how to read all the different WX charts they have here on your Instrument Ride.
One more thing.. you can't just take the checkrides.. you have to have logbook endorsements from an FAA instructor that says s/he has given you the required aeronautical training and one that says that you can take the written test also (you can't just take it either). Don't go to FLightsafety... find a small cheap FBO (fixed base operator... read aeroclub)
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"..there's really nothing like a shorn scrotum. It's breathtaking, I suggest you try it"
[This message has been edited by weasil (edited 23 January 2001).]