Products made by the company "Just Born" are safe. I'm sorry I don't know anything about what's kosher or not. But their products are Peeps, Mike and Ikes, Zours, and Hot Tamales. My PA/TNA son loves all of them except we haven't tried the hot tamales as he is only two. For Halloween they have out little boxes of the Mike and Ikes-I stocked up on those!

SF,
Have you added any others to your list? My DD is starting preschool this fall and we're looking for other safe treats.
Other ideas that I put in our letter were-

SF - my son is also entering kindergarten this year, at a Jewish private school. They decided that all three kindergarten classes will be peanut/nut-free, but parents will still bring in birthday treats from an approved snack/treat list. I will supply a box of safe treats - enough for the whole class - in case someone brings in something not from the list. Then the unsafe foods could be sent home with the other kids at the end of the day, if need be.
The rest of the school is "peanut/nut-aware" but all parents in the school will receive the list, too, to encourage them to bring nut-free snacks, etc. Unfortunately, the kindergaten classes eat lunch in their rooms, so I'm still worried about how the p-free policy will be monitored/implemented. We've been planning mostly with the principal until now, but the teacher left me a phone message this week, saying that she'd do everything in her control to make sure my son has a wonderful year. It was soooo thoughtful - but I'm still nervous about the reality of implementation. We have a meeting tomorrow morning with the teachers, nurses, etc. to review his plan.
If you'd like, I can email the list to you. We're in the Chicago area - where are you?

Just wanted to add that if you can work with the teacher on creating a party list for specific days (we choose two salty things, two sweet things for food, plus any fruit or veggies if healthy food comes up), then do the calling to parents yourself, this could help alleviate most problems.
When I call parents, I give them a list or ask them to bring a specific item, then add the "you know, there is a PA child/children in the class...you might want to try X brands, but definitely avoid Y brand..." Most parents appreciate the help. Then somethimes I get the "Oh, you're Ryan's mom. He has the peanut allergy, doesn't he..." and it just opens up a whole new dialogue. I've haven't dealt with a mean parent yet.