Something I've noticed a lot of the guys I fly with doing is building 2 boxes. 1 larger box for all your tools & props & spare parts, etc. then a smaller flight line box for just battery, power panel & starter. This gives you a small light box to carry to the flight line with you as we leave are big boxes on the tables for any repair or prop changes that we need to do through out the day. This seems to work very well. I bought the GP Master Caddy for this very reason. It has what they call a satellite box for the starter, battery & power panel that unhooks from the main box. I like the idea of a smaller start box for the flight box. Unfortunately since most of these pre-fabbed boxes are made of sawdust & glue instead of real wood it is already starting to fall apart on me & it is less than a year old. I still like the size & configuration of the whole set-up so I will copy the whole thing in 3/8 ply myself as soon as I get motivated enough to do it. A friend has built his own like that out of 3/8 ply & they are very nice looking & very sturdy too. He does very nice work with wood.

I would definitely recommend building your own over buying one like I did unless you buy something like Ken suggested at home depot or lowes or some place like that. You might want to look at the ones available at Tower's site just to see which one you like & then just build it from there. Once you have seen it, it is simple to build without drawn out plans. Good luck in your building project.