external fuel supply for Honda-engined genny

I just re-worked my generator slide/swivel mount, and also attempting to build a sound-reducing enclosure for it (it's not a Honda EU "quiet" genny, but a Honda/Craftsman hybrid). I designed the trailer to be able to run the generator to supply power to the A/C, but it only has a small fuel tank, inadequate for more than a couple of hours runtime. I never did get around to making/buying a larger supply tank, so it could run all night if need be. The Honda EUs have special systems made for that, but not my generator. It does have a pulse-driven fuel pump, very short-time basis. I want to be able to run this one while I sleep, unattended, safely.
and the literature on the engine says it can draw/feed fuel up to 19 inches away from the tank, either above or below carb level (of course, I can no longer find the literature). I'm considering adding a feed line (on a tee), with a shut-off valve inline, and another return line to prevent oversupply, and simply dropping the end of the line(s) into my 5 gallon gas can, and run the genny that way. I read that the pulse pump will not overcome the needle/seat setting, but just in case, the return line seems needed. Either with or without a priming bulb? Or should I just add a marine tank, with all the equipment, even a fuel gauge? I really don't know if the pulse pump will actually pull from 12" away, and at a 6" elevation (projected placement on a stand next to it, both inside a soundproofing/cooling box), but I'm not familiar with outboard fuel systems either...it may overfeed the carb anyway. Any thoughts or experience doing this? I'll experiment if not (of course, outdoors, with a fire extinguisher in hand). I've run V-8 engines via a similar method (putting cars on a trailer, in the wild), but on a