Hi ctroxtell,
Bamboo, Aloe Vera, Beech Trees, Eucalyptus and many other cellulose sources are used as the raw materials to make various rayon or “semi synthetic” type fibers. They have a very soft feel to them and are very breathable and wick moisture well but IMO they are probably a little less durable than cotton (but this would also depend on the weight and specifics of each fabric). You can read a little more about them in post #2 here (and the links it contains).
I’m looking forward to hearing about what you choose.
Phoenix