Nice tank. Do you know the dimensions of those pieces? Number 3 looks very tall... maybe too tall for the tank. It's worth nothing that your tank is nice and wide as well, so it might look better if you can emphasise the width by drawing it out with wood that stretches across the tank a bit. Those pieces look like they would be sort of balled up in one part of the tank.
Those pieces look quite wirey and flexible, as well as very light coloured. In my opinion, it's not as aesthetically pleasing as a more robust piece of wood. I have little experience as I am just starting my first tank, but initially I got a large piece of mangrove root - probably a piece from higher up the base of the tree - which looked more like this (but I could NOT get it to sink at all):
I eventually decided on sumatra driftood, which I think looks beautiful, and is nice in that it has lots of thin, complex and protruding branches like the mangrove root. However, it's more solid and is thick enough to look good with moss attached, I think. This is just my opinion, but you might want to consider sumatra driftwood. You can get larger bits like this:
Or smaller bits like this (of which I have 3 in my tank):