Yes the 44-45mm bit will work just fine for the 1"... the 42mm looks like it is more for the 3/4" sch80 bulkheads.
And it would depend greatly on the material of the cutting board, but it should be just fine for the most part. The risk of melting the board is present but the wood templates do run a good risk of warping after the first use(especially with watering the bit the wood plate is gonna soak it all up) And I have no problems sealing the templates in urethane, but the cutting hole wouldn't be able to be sealed which is where the water will be present. I will make some up on both wood and some plastic boards and we will just have to trial and error it. My only hesitation with the plastic cutting board is that it lacks the thickness of a normal piece of wood which will help stabalize the drill bit, but depending on what I can find I may just glue and press several sheets togethr to form one thick piece