Mixing wood types can end up looking rather chaotic, although I'll often use a different wood if it's going to be completely obscured by plants around or mounted to it. Most of my anubia and java ferns are mounted on malaysian wood pieces.
There's a tremendous variation possible within each type of wood that it really comes down to what you find. Even ordering random pieces sight unseen, I've ended up with wildly intricate and interesting malaysian pieces and dead blah mopani--and vice versa!
www.manzanita-driftwood.com has a good variety of reasonably priced branched manzanita pieces, but be prepared with multiple options when you order--good pieces tend to sell fast. Really appreciate that you get a picture of the exact piece you're ordering and they give measurement for the length, width and depth of the pieces.