Based on the infor you gave, I would go with a tri-power with progressive linkage. You can run of the center 2bl when just cruising. I had a tri-power setup on my sbc before I put a Chrysler engine in my coupe and I was happy with it.
The old crossrams had a reversion problem. If you run one, you will notice a fog of mist above the carbs. Guys have tried to build anti-reversion dams in the chambers with limited success but I think you would be happier with either tri-power or dual quads.