For show quality you especially need to look at their feet they should have five toes on each foot and there should be good spacing between the fourth and fifth toe they should not be fused. They should have correct combs. Usually they are showed by their color, though they usually have separate category for mixed colored birds. Looks like the first few are Partridge in color than there is a red one and a blue one and the last one is also Partridge. Looks like a blue Partridge.
From what I can tell the blue one looks like your best bet for showing. Check the feet and the comb! Good luck with your birds.