Here are some INTAKE air flows for OOTB Indy EZ standard port, OOTB Edelbrock RPM and OOTB TrickFlow heads, all from the same flow bench. I think I would use an Edelbrock RPM before I used a standard port EZ on the 383.
Lift...............Indy..............RPM...........TrickFlow
.100..............66................70................74
.200.............127..............145...............150
.300.............181..............205...............221
.400.............232..............245...............274
.500.............272..............260...............322
.600.............299..............276...............336
.700.............315..............282...............333
Valve sizes...2.19/1.81......2.14/1.81.....2.19/1.76
So, if the Indy EZ is going to work on a 383 bore, the TrickFlow certainly will. Pretty sure younggun2.0 is running TrickFlow heads on his 383. Even with 1.6 rockers on the XE285HL I believe you'll be okay valve to cylinder wall, and the valve notches on the KB pistons should give you valve to piston clearance. But as always you need to measure those things during the build.
As to the most future potential? The TrickFlow hasn't been tested there yet, but with an intake valve size increase the Indy EZ can go 360cfm+.