Sorry Monty, no offence intended. I just really like the strength and rigidity of the plywood construction I used and may be a little over-zealous in championing it.
Any solid, stable hardwood or even a softwood like D Fir will work fine. I used Arbutus because it is a local “specialty” wood and it has good characteristics.
I am pleased that you like the vices (vises). Let me know if I can be of any help.
The early bird gets the worm but its the second mouse that gets the cheese.