My suggestion is 1. WYK and 2 SFXC. If your son is a Band 1 student, he should be allocated to either school. This is because a small amount of Band 2 students have been allocated to SFXC in recent years due to not enough Band 1 boys in YTM district.
However if your son is a borderline Band 1 student, it is worth to set a security line earlier at 3rd or 4th choice in case there is a wrong estimation of banding.
Try to avoid those coed schools as the outcome will become more unpredictable.
Both of them are good. Both offer a lot of different activities. It depends on the personality of your child. In terms of results, QES should be a bit better, but the difference is not big.