there was little interest in this, but I thought I'd come back and offer up results..
I ordered a tool box, based on dimensions, and ended up with a DeeZee, and only because they were the only ones that made a box in those specific dimensions.. turns out, the dimensions were wrong, and the box was smaller than advertised.. that's what I get for buying anything DeeZee, who are known crooks..
I ordered a tank from Union Hydro, an RDS rectangular 60gal job.. can't say enough good about that outfit or the tank itself.. it was precisely as advertised, delivered timely, and met every expectation.
I decided another AirDog 150 on board may be a good thing, in the case of failure of the primary lift pump duties, I can swap this one in... also, I don't have to have a stack of differing filters; just the ones for the AD.. it is turned on with an upfitter switch in the cab..
I plumbed up a (normally closed) solenoid valve that toggles with an upfitter switch and through a timer board.. the timer board operates for right at three minutes (or transfers a 1/4 tank of fuel to the main tank) and also triggers a couple of 155db buzzers to remind me to turn off the pump.. it closes the valve at the end of that three minutes so I don't spill.. All I gotta do is wait for the main tank to drop to less than 3/4 tank, tap the upfitter switch, and transfer filtered fuel.
here are some pics of the control panel/pump, before, and after.. I didn't mind losing bed space because I mad a nice little platform/bed for the dog while I travel.. what can I say, but that dog has it good..
I had to drop the factory tank, and took that opportunity to install a sump on it, but also to tap the roof of it with a bulkhead fitting and a 1" fuel hose for the transfer.
I had to fabricate those little panels that go over the wheel hub, and raise the DeeZee box to flush with the top.. I cut and covered some boards to fit between the rail and the tank/box, to tidy things up... all towing straps and other stuff is under the passenger side hinged board, and the pump/control board under the drivers side.. I even mounted a spare battery in the deezee to power the on-board air compressor hidden under the passenger flip panel, and I'm going to use the space under the deezee to conceal the hose for that compressor.
I also wired in a 12v cigar lighter outlet over the drivers side wheel hub for gadgets I often use.. the top of the box is flush now, and has isopore mats under the carpet to make it flush and insulate..
overall, I'm happy with the results.. it appears it will suit my needs just fine.