This link will take you to a sizing document made 2 years ago, but still valid: Ski Sizes by Age Class.pdf
The only changes I would make to it are to say that for the U-16 skiers who have the biggest dreams, they should move to the FIS ski (whenever possible) as a 2nd year u16. It is just easier.
And for those FIS aged skiers (u19-u21) who do NOT plan on racing any FIS races at all (Northwest Cup would be their highest level), they DO NOT HAVE to have the newest FIS skis. Some of the Masters' skis are much less demanding and more fun.
Here is a link to the USSA requirements. A quick glance will let you know that CMAC has more stringent recommendations than the USSA requirements. This is because we want to maximize Skier Development.
https://www.skiracereg.com/data/uploads/event_212_1.pdf
Happy Ski Hunting! See you at the banquet.