Don't forget these...
A sharp Japanese kitchen knife should be paired with an adequately high quality cutting board. One such brand recognized and used all over Japan is Hasegawa. Delivering high quality cutting boards that are soft on the edge of your kitchen knives, with an assortment of series and sizes.
What makes this for professional use is largely the size. At 23.5" long by 14" wide, it can comfortably be seated on your prep table and still give you ample room to reach into the sándwich top. And at 0.75" thick it will take a while before your knives consume the entire surface of the board before getting to the wood core, even in heavy professional use.
These cutting boards are made out of high quality polyethylene (plastic). As such, it makes them quite stain resistant and resilient to the occasional deep cut. Given the core is made of wood, it gives the whole board a lot more rigidity and less flex. Oddly enough even with a wood core, these Hasegawa cutting boards are still 30-50% lighter than cutting boards made out entirely of plastic.
Given this is a softer board, it is ideal for your delicate cutting of fish with a yanagiba. As the board is somewhat 'sticky', it also means your pieces won't move.
The added rigidity of the board also means it won't warp or bend if you put it in the dishwasher at high temperatures.
As for hygiene, you don't need to be worried about the wood core. It is covered and sealed under thick plastic layers and unless the board becomes grossly damaged, the core will never be revealed.