This is most impressive, Duane! That'll serve you well for a long time.
How much are you going to raise the walkway? Any concern about water pooling in that walk area? And what kind of material are you filling these beds in? Because of their depth I would be tempted to fill the bulk of it with rotted wood and finish it with 6 inches of compost at the top.
I like your idea of barrels gravity feeding a drip system.
