I suggest that you opt for the 121 ... after the European (or SA) exams you'll find it a breeze ! The flight exam on the other hand will depend very much on who you draw as an examiner... The oral can be pretty tough, the examiner will have the results of the ground exam and will be able to spot any weak points... it can go on for several hours if you're unlucky and after that wringing out you'll have to take the flight test immediately afterwards. The FAA don't seperate the General Handling and the Instrument rating as is done in Europe and probably SA... you get it all at once ! I had to do a lot of research on the flight test as the flying schools in the US are not accustomed to preparing candidates for an ATP check-ride, typically their students do the CPL then go off to fly freight or sit as SIC on a commutor a/c... then do the ATP as part of a type-rating when preparing for the left hand seat... my check-ride consisted of five approaches (a seminole) 3 non-prec/2 prec... all single eng. The guy was changing runways on me/failing DME CBs to check my ability to cope with different minima.. Unusual attitudes (under the hood) plus the usual stuff, stalls etc... 2.5 hrs, he was pretty tough but fair... I'm sure there are tougher... and and easier.. Good Luck..