Solid roller cams HV oil pumps?

I was planning on running the lighter weight synthetic oil. What seems odd to me about the distributor gears is that the with bronze you can run the high volume high pressure pumps while the melonized steel gears say not to.
The distributor gear regardless of material would be happier with the standard pump.
Do the roller lifters lower the oil pressure any versus flat tappet?
I realize that with the roller cam I will be doing periodic checks to make sure my lifters are not spitting needle bearings everywhere and that my rockers are in adjustment.