I just converted NZ commercial to FAA commercial. Pretty easy. The only hours I needed were my night and night xc time. They issued me a private pilot certificate a month and half after I sent all the paperwork in the CAA and FAA for lic. verification.
You need to do at least 3 hrs with the instructor from the school you are going to use in preparation for the practical test. Before you can do the practical test (flight portion), you have to do the written exam and pass above 70%. There is prepware out there that will give you 90% of the questions they can ask you and you pretty much just memorize the answers and the same questions will be on the written exam. Once all that is done, you can schedule you FAA check ride. The day of the check ride, you will have an oral exam. Mine lasted about 3 hrs of oral exam and 1.5 hr flight. The first portion of the check ride was a xc, did a few legs of the flight and then back to the airport to do all the emergency procedures. Overall pretty easy. I suggest getting and FAA medical. It's is very easy and cheap to get a medical in the US.
And any of the hours after PPL, including dual instruction flights, are considered PIC.
Link to the Oral exam, with the questions they can ask you on the day of your check ride.
http://www.amazon.com/Helicopter-Oral-E ... 1560276088
Link to the prepware for the commercial written test (these are the exact questions you will be tested on).
http://www.amazon.com/Commercial-Pilot- ... helicopter
Here are the minimum hours needed.
■For a helicopter rating.
Must log at least 150 hours of flight time as a pilot
that consists of at least:
(1) 100 hours in powered aircraft, of which 50 hours must be in helicopters.
(2) 100 hours of pilot-in-command flight time, which includes at least—
(i) 35 hours in helicopters; and
(ii) 10 hours in cross-country flight in helicopters. (3) 20 hours of training that includes at least—
(i) Five hours on the control and maneuvering of a helicopter solely by reference to instruments using a view-limiting device including attitude instrument flying, partial panel skills, recovery from unusual flight attitudes, and intercepting and tracking navigational systems. This aeronautical experience may be performed in an aircraft, flight simulator, flight training device, or an aviation training device;
(ii) One 2-hour cross country flight in a helicopter in daytime conditions that consists of a total straight-line distance of more than 50 nautical miles from the original point of departure;
(iii) One 2-hour cross country flight in a helicopter in nighttime conditions that consists of a total straight-line distance of more than 50 nautical miles from the original point of departure; and
(iv) Three hours in a helicopter with an authorized instructor in preparation for the practical test within the preceding 2 calendar months from the month of the test.
(4) Ten hours of solo flight time in a helicopter or 10 hours of flight time performing the duties of pilot in command in a helicopter with an authorized instructor on board that includes—
(i) One cross-country flight with landings at a minimum of three points, with one segment consisting of a straight-line distance of at least 50 nautical miles from the original point of departure; and
(ii) 5 hours in night VFR conditions with 10 takeoffs and 10 landings (with each landing involving a flight in the traffic pattern).