Have your checked out a carnival store in your area?
It is "one stop shopping" for your event. We, too, are a K-5 elementary school and have used a carnival supple store for the past 2 years.
They not only have a selection of games, but you can even pick out all your prizes for the booths too! The people who work there really know what is "new and hot" for the kids. We have had much success at our school using this type of company.
Another great thing is they 30 day invoice from the date of your event, that means your PTO does not have to come up with $$$ before the carnival.
Need everyone's idea's for games & prizes for a Spring Festival for grades K-5. We are a new school and this will be our first festival. We know the festival will get larger each year but would love to hear your ideas.