It would be nice if everyone's answer was the same on this one.
I can offer some guidance, which hope will be of some help.
Fundamentally, additional volume is needed if the bearing clearances are large or something like that.
A high volume pump is definately a part of a fully thought out system. It has taller rotors, and will suck up more oil per minute than the standard pump.
Thats not always good. That extra volume could end up getting blown out the relief valve, or sitting under the valve covers etc slowly making its way back down. In these cases the sump level is low, and the oil aerated.
Here's the way I'd try to approach the system.
Use rpm and the bearing clearances to get a sense of whether the Volume per minute will be beyond a stock pumps capacity.
A deep pan (assuming ground clearance is not an issue) will never hurt. OK a little slower on warming up. No biggie.
Decide about going to a larger pickup after deciding about whether its going to need more volume per minute.
Pick a spring based on rpm. A high spinning engine will likely do better with a higher spring pressure.
Select an oil grade for the bearing clearances and temperatures.
