Carb CFM recommendations

KISS...
Get the as you described classic Edelbrock 1406 and leave all the troubles behind. It will fit right on your Edelbrock manifold no problem. A couple simple adjustments and you'll be off with no problem. Actually you may have to jet down or quite possibly just tell Edelbrock your altitude they may send it pre-calibrated Jet and metering rod wise and leave just a little fine-tuning for you which is easier than falling out of your bed....