Expect me to advocate the opositie.
Drilling holes in the sky on a basic airplane is a waste.
Travel with your son to the USA and visit the schools on your short list.
Spending $4-$5k on selecting a school can save you 10's of thousands.
Find a school experienced with non-US students and I don't mean Chinese or Indian.
Explain to the school that your son will be there for PPL through CPL ME IR
Why is this important?
Because PPL training is not equal.
I would train a PPL student with recreational intent differently then a PPL student with professional intent.
When a student is proficient in steep turns at PPL level there is no reason why you can't add 5 degrees and get them proficient at CPL level already.
Some of the FAA required CPL maneuvers are perfectly suitable to be taught during PPL. Also more attention to checklist usage, call outs and things like radio navigation if you know the student will do their IR next.
For a 'recreational' PPL is would spend more emphasis on dead reckoning and pilotage and with a 'pro' student use more radio navigation during their PPL dual and solo and night cross countries.
Now you need a Chief Flight Instructor who understands how to do this.
Choose an airplane type for the PPL that will be used for the IR next.
Choose an IFR equipped airplane for the PPL.
You don't want to use the simplest cheapest aircraft for the PPL and then have to do the IR in an airplane in which they have no flight experience.
Yes the PPL will be a little more expensive but you save 1000's on the IR by using an airplane that they already have 45-50 hrs of flight experience in, know all the checks, power settings , equipment and such.
Otherswise you can easily add 10-15 hrs onto the IR.
PPL and IR under part 141 training as it allows you to do the IR right after the PPL.
CPL training under part 61 as this allows more flexibility.
Log EASA compliant from day one.
Do all the required time building on an IFR flight plan to gain IFR experience.
For a European student CPL SE then CPL ME.
This requires discipline but start studying for the EASA exams while still in the USA and plan taking the first 3 upon return to Europe.
Then complete and practical conversion.
Alternatively enroll in a combined Academic and conversion course, ideally using the same type of aircraft as used for previous training.