for a field box you might want to consider this box that a bunch of people use
http://www.rcuniverse.com/showthread...247&forumid=63
I got one at our feild and after people saw it about 3-4 more showed up, also Bill Hell and a bunch of the guys in his are have them.

it has 2 halves so that you can put all your normal starting stuff in the bottom and take that down to the flight line and leave the tools in the top or roll the whole thing on its wheels.

as for what you need in the box I found that the greater the distance between you and your supplies, the greater the need will be.

in other words, bring everything you can, because you never know )