The 470-500 cubic inch engine doesn't require but certainly can USE a ported head no matter which one you choose.
The head with stock port locations and the greatest power POTENTIAL is the Indy EZ.
However......the Victor 440 intake and ported Edelbrock RPM heads, with the stock intake gasket size, that flows 305-310 cfm @ .600" and the hydraulic flat tappet, will still easily give you a 640tq/600hp 500ci street engine, all by 5800 rpm. Almost anyone's CNC program, or a competent hand porter can achieve those flows.
Depending upon the cam duration, I suspect you may be able to run on 91 octane with the 84cc Edelbrocks and the cam you have chosen.
ANY aftermarket aluminum head, properly ported, can make in the 800 HP range, this INCLUDES the Stealth and RPM heads. I have a Mopar Performance Stage VI head, that uses standard offset rockers, part number P4529335, that I measured at 90cc's in the combustion chamber. They too can be ported into the 800HP range.
The EZ head is not going to give you an extra 100 HP, as Russ claims, without doing the improvements suggested by Brian and using the Super Victor 440 or Super Victor 440 Max Wedge or another Max Wedge style intake. This is because, the box stock RPM will outflow the box stock EZ to about .500" lift.
