I see the job trailer cult has struck again...
I've used a Knaack box for over ten years and has worked pretty good. My question with the trailer - if it's parked on the street and you are working in the backyard, are you carting all the tools back there? Whats the man hours for that? If you have a job trailer then what pulls the skid to the job? Oh right, now there is another trip or truck involved...
I unstrap the box from the back of the 550 dump and the little skid or big skid takes it back in one trip, another trip for the splitter and compactor. I can also roll it through a gate if access is limited. I fit my brick extreme and stand, quickie saw, lazer, steel stakes, buckets of common hand tools, shovels, rake, small screed boards, extension cords and some other misc. stuff. It does have to be 'packed' for everything to fit and that does get annoying but for a longer job I stack the shovels on top if it's secure instead of packing it up every night. It is lockable and weather tight. If I remember right, I spent around $300 on the box.
Do or do not. There is no try. yoda