accumulators are great for momentary losses in oil pressure. A sudden turn at high RPM where the pump catches a quick gulp of air. The last time I saw an accumulator fired off was with the engine off with cold oil and it only lasted 10 or 15 seconds. with the engine running and warm oil, I am sure it would dump even faster. I don't remember what size the accumulator was.
The big benifit of an accumulator is on high RPM conditions where a lack of oil pressure welds the bearing to the journel snapping off the rod, spitting parts all over the bottom of the engine
As far as even being a problem, it would only occur if you are real steep nose down or on your side. If you are on your side, you are not going to be able to get back up in a couple of seconds.
Generally you are not doing 6000+ RPM driving up a hill in reverse. If this is a common thing for you, then you may want to consider a dry sump.
as for dry sump, there are 2 basic ways to drive one. Standard and sprint car style. Standard uses a cogged belt and runs like another accessory on the engine. Don't want to loose that belt. Can't get it at the local NAPA. Sprint car is direct drive off the cam on the front of the motor. Adds about a foot to the engine and where do you put the water pump? Those sprint car waterpumps are not designed for good flow at idle, just low drag at high RPM. There is another rare type that drives off the back of the engine on the bellhousing, but that is not praticle to even consider since you need to run a direct drive (no clutch) or similer. The dry sump systems require several stages (pumps) to be effective. General suction areas include the front of the pan, back of the pan, and valve covers. For a Bronco application, you would need several valve cover suctions. Suction lines do not take being T'd very well. For an example, take 2 straws and put one in a glass of water and leave the other in the air. Try sucking on both at the same time. You just get air. So you will need a 7 stage pump to make a bronco have oil pressure all the time. 1 port at each corner of the valve covers = 4. 2 ports on the pan. And 1 port to send oil back to the engine. For an oil tank, you should be looking for aircraft because the car ones still don't like to be upside down.
With all that, I do have a good place for an accumulator. Start up pre lube. Besides, most engines are quit tollerent running a short time with minimal or no oil pressure. Since the rear sump pan goes dry pointing down hill, you usually just idling anyway, not working the engine.
What ever you do, do NOT turn off the engine and coast down a steep hill. The engine needs to be there to slow you down. All the parts are still wet and covered with oil for a while after you shut off the engine, or the pump sucks air. There is still some lube for a while even without pressure.
Is that enough ranting?