Upgrading fuel system need recommendations

[sst1226]

Have a 69 Nova currently with a 500hp 396 and a 750 double pumper. My current setup works for this combination but now I'm building a mild 509 that will make somewhere in the 700hp range and have a Dominator.

Currently I'm running a single Holley black pump with #10 line to a y-block sends 2 #6 lines to 2 holley regulators and then feeds the front and rear bowls of the carburetor.
Below is a sketch of the system as it is now.
As you can see, I'm looking to step into the 21st century with my fuel system.

What are your recommendations for the new motor, I'm not sure that this setup will be enough to feed it. I searched around and it seemd like the magnafuel pumps are the way to go.
Could someone give me a good pump/regulator recommendation?

Also, do any of you route your fuel system this way?

Does anyone use return lines?

Thanks in advance!