Is 14U Platinum division considered tier 1? Or is it really good tier 2? Also, for 2009 next season, do most of the good tier 1 players move on to high school, prep, academies? Or do they stick around EHF and E9 full season? Or maybe they do split season?
In addition to the advice already given, I'll add, some more. As already stated, U14 can be a roll of the dice.
If your son is going to try out for HS, find a u14/u15 half season team. Don't worry if he doesn't make varsity as lots of teams will be looking to add players after Thanksgiving and some will give fairly steep discounts for the second half of the season if they lost more players than expected.
If the organization you are at doesn't field multiple teams per age group and you are committed to a full season, strongly consider switching programs. It's not uncommon for an organization to combine multiple U14 teams into a single team after Thanksgiving which is obviously not an option if they only have one team.