They should be fine together... just make sure they all have enough space and watch that than none of the littlest ones get picked on or trampled. I'd be also sure to provide 2 or even 3 feeders and waterers for that many babies so nobody gets crowded out and goes hungry or thirsty. And you may need 2 different heat lamps so everybody can get to the warmth if they need it.
Keep in mind that the keets require a higher protein starter food than chick starter, so try to find a Turkey, Pheasant or Game Bird starter feed containing between 25%-30% protein and make sure it is medicated with Amprolium to prevent Coccidiosis. The chicks will just pass the extra protein, but the keets need it to grow and develop at the proper rate.
At two weeks they will like perches about three feet high. Eventually they'll spend most of the evening on them and it makes a nice get away during the day. It won't be long before they can get on a perch that is six or seven feet high.
These roosts are around 3 feet and 5 feet tall in my old (free) Miley horse trailer that I converted into a keet brooder... plus they have the the saw horse that the heat lamp is hanging from to roost on for the smaller babies that aren't quite old enough to get up on the perches with the big boys yet... (I swear they all poop on that lamp on purpose! lol).