[X] [RIGHT STUFF] FlightExperience - This would encompass those with extensive piloting experience, as that stood as the greatest stand-in for high-G flight available. This would largely mean your first spacefarers would be veterans of the Third Great War and the Revolution.
[X] [RIGHT STUFF] Inclusion - There was an argument to be made that the colonized peoples of the world had the right to the first shots at what would (hopefully) become a prestigious position. Choosing this would prioritize them - never at the expense of being qualified in at least two of the other considerations, but it would open the doors more to them, thanks to no one having been a spacefarer before, and what needed to be known could be taught.