You can find it at your local Riteaid or Walgreens. As for woods, any closed grain hardwood will be fine such as Cherry, Maple, walnut, Beech, Hickory, Purpleheart ect.
Do not use soft woods like pine or ceder. Do not use open grain woods like Red Oak and Mahogany.
Don't worry about so called toxic woods. It is the wood dust that can cause problems. Cutting it with a knife will not present problems.