Again, Midland GXT (GTX whatever it is) is what you are looking for.
Tri-Squares are nice, but are only different from regular FRS/GMRS radios in that they operate on the 900mhz band. They still Tx with .5w which can get lost in the clutter of an airsoft field.
Ham style radios operate on the 2m or 70cm band (FRS/GMRS is also on the 70cm band but restricted to .5w Tx power) and typically operate at 4w-5w. This means more power behind the transmission to cut through the clutter and trees and bushes to get the signal out. They are more expensive, and are more regulated. They also require more technical programming, and comprehension of the 70cm band (for use in an airsoft environment).
http://www.amazon.com/Midland-GXT760VP4 ... 407&sr=1-3
Get a buddy to go in with those and you get a decent beginners radio to use. Please for the love of god learn how to properly communicate over a radio.
RADIO ETIQUETTE
Allow 2 seconds before beginning a transmission after keying the microphone.
Be brief and to the point; keep the channel open for others to use.
Speak directly and clearly into the mic 2-3 inches away from your mouth.
Use the name of the person you are contacting and identify yourself as well: "Shasta to Jen.�
Acknowledge that you have heard the communication: "This is Jen. Go ahead."
When identifying your location be as specific as possible. There are a million "bushes by the tree".
Don't have conversations over the radio. Say what you need to than shut up. Chances are someone more important is trying to say something more important.
DO NOT HOTMIKE. Hotmike means to keep the transmit button engaged longer than necessary. We don't want to hear your overweight heavy breathing. Disable the VOX setting, and only push the button when you really have something to say.