I can get a gale-force wind through the knee vents in my '59!
I put a moonroof in one of my Tempos and even slightly cracked it lets a lotta heat out when parked and moves air nicely when going. I think the aero hit on a window that tips up like that vs retracting is quite small.
Power vs Crank windows: do these weight estimates include all the extra wiring and switchgear? Power windows and locks really make for fistfuls of wires going all over, especially to the driver's door.