New hires get PHENOM, Praetor or Challenger. Globals are on their way out (not sure any are left in the US at this point). Gulfstreams are a different animal called ILC (International Large Cabin). They are teams of 5 (One of which is the Commander, i.e. boss) that must staff both seats all the time. You fill out an internal application and the Commanders with openings on their team will call and interview you. I knew someone who got awarded a G450 posiion within 6 months (already typed). Its kind of a moving goal post, when I started they pretty much wanted you to be at least a CA and preferably an IP, with most coming from the Phenom. Recently you have seen more CA from the Praetor and Challenger move over. They will not hire you for ILC if you are over 60 (was what I heard)