Upload & Sell: Off
Funny, I too shoot weddings and was looking for something similar to the Einstein & VML solution but the closest equivalent I've found so far are the Profoto D1 500 Air and Elinchrom 600RX which in the end is not really a replacement to the Einstein & VML. I tested the Quadra and found that the 400w is just not quite enough, it’s OK for shooting the couple but not enough to cover for group shots in the sun. Also, it’s not practical to shoot at full power because of the refresh rate, so I only shoot at ½ power or below most of the time in order to keep the refresh rate high enough for multiple burst, which means using 200w for the Quadra instead of 320ws on the Einstein.
You could also consider the Manfrotto Nano (1kg) or other Chinese equivalent lightstand and a double fold white translucent umbrella to save on weight. This is pretty much my destination wedding lighting kit.
PS: I took that first photo you posted in Vegas salt lake on a cloudless day, that was with the Einstein with the above kit at ½ power. That kit traveled 14,000km from Perth to Vegas, so it’s quite portable.