I use two bucket boss rolls and carry them in a bucket boss bag. One roll holds end wrenches, 10mm to 19mm, 12" pry bar and I forget what else.. Not much. The other holds 3/8 sockets, 8mm to 19mm, and like Jimmy, I carry deep sockets for a couple sizes. Then I have basic pliers, needle nose, channel locks, a couple screw drivers, a couple different sized drifts...
These trucks are basically built with 6, 8, and 10mm nuts/ bolts. If you can't fix it with some basic tools, I think you're doing it wrong.