I've come to the conclusion that Ayu will deffo take the #1 spot. Even if Koda manages to sell more, Avex will always work an extra 5-10k or whatever is needed to make sure her streak keeps going. Here's how I realistically think it will go keeping that in mind.
First week sales
Ayu: 65-75k
Kuu: 50-70k
However because L is being released the following week "crossroads" will probably free fall off the chart with total sales looking something like this
Kuu: 70-90
Ayu: 80-85k
Why am I not surprised that Avex would pull something like this .
. 
Someone post a video of her singing one of these songs live 
