Carb Guru Opinions Requested

* Car: '69 Dart
* Planned engine combo: 408cid, 10:1 compression ratio, EQ Magnum heads with 62cc chamber and 2.02"-dia. intake valves, cam specs 230 in./234 ex. @ .050 w/108 centerline .501 in. lift/.513 ex. lift, Edelbrock RPM Airgap intake, TTI 1.625"x1.75"x3.0" step headers, 3.0" exhaust to the rear bumper
* Trans: 200-4R, manual-shift reverse pattern w/2800 stall lock-up converter, 2.74/1.57/1.00/0.67 spread
* Rear: 8.75 Sure Grip w/4.30:1 gears (2.88:1 gearing equivalent when in OD)

I'm strongly leaning toward a 750 cfm double-pumper carb w/annular boosters in order to maximize fuel vaporization for best possible mileage (yeah, I want the best of both worlds), but I realize the annular boosters are larger and cause a slight reduction in air flow volume - resulting in increased air flow speed.
Is this air flow volume reduction enough for me to consider going to an 850 cfm carb instead in order to have enough volume for the engine? Or is the volume reduction too small to be concerned about.
I ran a strong 340 build on the street back in the mid-70s and had to go to an 850DP in order to keep it from shooting ducks on the top end.
I want to buy the correct carb the first time and not have to build an inventory experimenting.

Thanks for your input!