Nona,
What JB said is all correct except for the issue of ATPL you must hold a stand alone FAA IR. So getting an IR on the basis of your current IR will be of no value to you. So I suggest taking a IR skill test after you have taken the IR written exam.
Also now would be a good time to look in your logbook to see if you meet all the requirements for the issue of certificate (FAA calls it certificate rather than license as there is no expiry date).
For IR-
1) You must have 40 hours of IF time (which I am sure you do).
2) You must have 25 hours of dual IF instruction received (I am sure you do).
3) You must have a long IF cross country with three different approaches at three different airports, total distance > 250 nm with one leg > 100 nm.
For CPL-
1) 2 day VFR and 2 hrs of Night VFR cross country instruction received.
2) A long 300 nm cross country (SOLO; some examiners are very particular on this and they will not accept any flights with co-pilot or even your wife along with you, the FAA regs reads solo and not pic).
3) I suggest going straight for MEP CPL that way you wont have to learn all the ground reference maneuvers.
For ATP:
1) Skill test (it is a glorified IR skill test)
I also suggest purchasing IR/CPL/ATP oral guides. These books will give you guidelines on what you can expect during your skill test (FAA skill test involves an oral exam and if you pass it you procede to flight part).
For your written exams you can purchase either Jeppesen or ASA or Gleim guides. They also make softwares to prepare for the written exams.
You will also be required to hold a FAA class I medical.
Everyone who is not an American citizen is required to have authorisation from TSA before you will be allowed to undergo training. You can find out more about it at
www.flightschoolcandidates.gov
It is a long paper work exercise but can be completed in 4-6 weeks as long as you contact a school who can design a package just for you.
Since 9-11 FAA has stopped doing direct conversion from ICAO atp to FAA atp. Also unlike other countries FAA requires you to individually pass the written exams ie IR/CPL/ATP. Just because you have passed ATP Exam doesnt give you passes in IR or CPL. You will require an instructor to sign you off to take the exam for IR and CPL. For ATPL no sign off is required.
Hope this helps.
- DesiPilot