I stick with the Malaysian driftwood because the one time I tried the Mopani, I had fungus issues even thought I boiled it for a few hours before putting it in the tank.
Having said that, if you do go with Mopani, you might never have an issue but it is something to be aware of. If you put Mopani in the search post feature, you'll see lots of conversations about it. Here's one of the links that might be helpful for you:
http://www.tropicalfishkeeping.com/beginner-freshwater-aquarium/mopani-wood-good-bad-107629/
Having said that, if you do go with Mopani, you might never have an issue but it is something to be aware of. If you put Mopani in the search post feature, you'll see lots of conversations about it. Here's one of the links that might be helpful for you:
http://www.tropicalfishkeeping.com/beginner-freshwater-aquarium/mopani-wood-good-bad-107629/