I finished building out the basic framework to the left side cabinets and then I took the other old carpet covered bed-bench and mounted it temporarily for this week's trip.
It was a happy coincidence that my old bed benches happened to be the right size for cabinet tops... I just cut the one off with the table saw for the island... the other one happens to be sized perfectly and didn't need trimming
I then finished in the end of the cabinet in front of the fridge that the subwoofer is behind. Eventually this will be halved in height and a drawer or two will go in the top half above the sub.
Eventually I'll fill in above the fridge when I build the cabinets to the left of it.