I have a CARSCAM 720p HD Dash Cam that works very well. Has 32 GB TF Card and is quite good. Loops over when card is full and captures the image in 2, 5 or 10 minute segments. I ordered it directly from China, arrived in 5 days to my door for $68Cdn. Just put CARSCAM HD Car DVR in your browser and it will come up.
I have a 25 gallon tank in the back of the pickup with a tap outlet on the bottom. I just hook up my white hose and attach to the trailer tank water fill, open the valve on the storage tank and let gravity do its work. Never have to take the water tank out of the pickup and do not need a pump.
One of the problems you will find with the additional office trailer is finding a site large enough to fit both Class C and work trailer on with hookups for both. The custom trailer would require its own electrical system, A/C etc set up for work. Might be difficult to work with.
What about a toy hauler where you could outfit the garage portion for an office so one could work in the garage area while the other works out of the living area? Might work.
Had a 2005 extended cab 2500 with short box and 2WD and 4:30 gears. It was a towing monster. Loved every second driving it. Towed a heavy 5er with no problems. Loved that truck but had to go with a F-350 with V-10 as the 8.1 was not available in 2008.
Your biggest problem will now be mould. Yes I would contact insurance. We too also turn off all water even if going for a walk and make sure pump is off too. I have seen to many units with water pouring out of them over the years.