I generally try and avoid connecting at US airports if I can, since most of them are pretty awful. JFK is particularly painful if you have to change terminals, since the security lines are so long.
I second Swiss Tony's suggestion to be flexible with your dates on the direct flight from Orlando, or to fly from Tampa, which is also a nice airport. The direct flight from Tampa is generally cheaper than the flights from Orlando.
I haven't flown from Miami in a long time, but I think it would be a much better bet than JFK.