Are you sure you want to fly for an outfit with only 3-4 routes total? The scheduled service is very limited - wouldn't that get boring after awhile? AMS-Houston and back and soon FRA-EWR over and over and over again. I am thinking that Amsterdam-Houston flight would also get a bit uncomfortable in that tight flight deck after a few hours... At least the A319CJ has a somewhat roomy flight deck.
If Privatair were using the BBJs in a more traditional charter role I am sure that would be far more interesting (unlimited destinations). Good luck regardless of your choice.