Most of the contact details seem to be up to date. Ok, it's some months agon that I've been with the SonAir guys...
Keep in mind that Angola is Africa so that people are not really keen on emailing (reading and replying) - do not expect a reply. On top, SonAir sometimes experience problems with their email system.
Furthermore, some of the guys almost speak no English. Portuguese would help your communiction a lot.
I think F50 pilots were locals, if I remember correctly.
Good luck!