Normal walkies work fine if you are just doing local events. I use a Midland GTX 300, comes with 2 radios, 2 headsets, and dual charger for around $70.
If you plan on going too national events then I suggest you look into higher quality radio's. The distance you need to cover at national events are huge, so something like a Soridin or an Icom would be beneficial. If you play with people who go too national events grab a walkie that has huge range, as you might be overpowered by the nicer radio's. I use my GTX's on high power, which isn't great if you are playing for multiple days(I usually don't), but I simply cannot transmit on low power because I get overpowered.
sticks