I'm going to remove all the drift wood and leave the tank free of plants. I was chatting to the feller from the local plec specialist, who had personally been collecting these fish, and he said that there was only sand, mud and stones in the areas he collected them from. (There may well be the odd bit of wood in the actual river, so for this reason the 1 piece may stay, especially as there are 3 baby L333's lodging in there who wont vacate
As for tetras, I may go for penguin tetras (again, suggested by the chap from the LFS)
I've had a play around with the current and added some slate pieces to the tank today so some more pics to follow.