Looks like a fun challenge. I can only imagine how hard it is to aquascape a large tank.
I think you need battle the symmetry a little. Having one long piece of wood, even at an angle, will probably look too symmetrical to appear natural. I like the Amano school of thought where a lot of tanks have focal points at about 2/3 from one side of the tank.
I think the trick is to battle our tendency to space things out evenly and create order. I like tanks that look more natural and include some contrast between density and space.
Another interesting approach is to create one high side and one low side. Cut, break, or bury about 1/3 or the log, and then create a beach with gound cover and/some open space on one side of the tank, and more densely planted, taller plants on the other side. This is a random online image of an assymetrical tank: