I've also found that wearing a helmet can really give a boost of confidence because it helps you feel safer. And when you feel safer, you'll be more brave in addressing these guys problem behavior. Do you have a lunge whip or perhaps one of those fiberglass "wacking sticks"? Those can help keep the horse out of your space. I'm going to plagarize Clinton Anderson here - everytime the horse makes you move, you lose. Everytime you make the horse move his feet, in this case away from you, the horse gets a little more respectful of you.
Given your circumstances, if nothing else, I'd suggest that you read anything and everything about foals and horse training that you can get your hands on. You can't magically become a horse trainer from books, but the more you know about how horses operate, the more ideas you have to pull out when you work with your babies. I personally found "From Foal to Full Grown" by Renate Ettl to be useful when I adopted my yearling, but there's oodles of great books out there.
It really seems like you need help though. You need to seriously consider sending them off to a trainer for halter breaking. Ground manners are just as important as how they behave under saddle. Maybe more important. You can't ride them if they are dangerous when you're on the ground.