One thing that you can be sure of... Whatever you put in it you will need the tool that is at home on the bench. No matter what you decide to do keep it as light as you can. There is nothing worse than toting your tools to the field then needing a rolling toolbox to get it all to the flight line and assembly area. I know, I used to use a rolling toolbox and have gone back to just a flight box. I figure it is easier to take more than one plane and if one needs a fix or repair and you don't have the tools handy ....fire up the other one.