First of to answer the OP questions. Take the courses where it is easiest for you. I also would take into account where you plan to sail. Learning on the Chesapeake for example will be a lot different than learning down here. Different conditions and different navigation issues, hazards, water depth, visibility wind speed etc.

There are lots of good options for this both in the US and down here. There are several good operations being run. Black Rock Sailing teaches on our boat at CYOA in the winter. I have sent people to Swain on Tortola and gotten good feed back. Virgin Islands Sailing school in Red Hook has gotten generally good reviews. One of their Instructors also works for us part time as a captain. Tortola Sailing School also seems to be getting good reviews.

As for the derail part of this thread the International Certificate of Competency. I went through this the year before last to do a Charter in Croatia. Despite having a US Coast Guard Masters I had to get one. If you have taken the necessary courses from ASA you can apply directly to ASA for a fee and they will issue the Certificate.

International Profficiency ASA

Jay