I no longer give any thought to the type of wood I use. When I find really old, truly dry wood, it is often impossible to tell what tree it might have been. What I do try for is avoiding tannins. That often means the wood is beyond recognition. After that I try to make sure I have a level field to play on without any wild cards. A bleach water soak and good dry afterward will let me be sure all disease, fungus, oils or other hazards are gone. The chlorine in bleach reacts with almost all organic things, even the wood itself. This reaction leaves no doubt about the things we can't see. The idea that the chlorine might some way stick inside the wood and come out later to harm fish ignores the facts. By basic nature, chlorine reacts with wood until one or the other is expended.
After making sure the wood is safe, it is a matter of watching what changes it may make in my water and doing something to counter any changes. If the PH begins to drop, a bit of baking soda might be called on. That never happens in my hard alkaline water.