You have found what is usually found, cookie-cutter woods or simple cut-off branches. Did you happen to check my website for mounts? I offer a "few". I am now in the process of completing another dozen mounts, oak, cedar, cypress, walnut, and hickory. I haven't been able to collect or prepare any mounting material for several months due to my back. I use nothing ordinary and everything I prepare comes from being "roughed up" (often for decades) in the Mississippi swamps, lowlands, and streams. Thus, every mount I have is one-of-a-kind and what I use and how I prepare the woods is done by no one else that I am aware of.
You can certainly use any mounting material you like but be sure you don't use any treated woods. Those wood preservatives are not kind to plants.