I have been using Ubuntu Linux since about 9.04 and have a moderate amount of experience with the Android OS structure so while it will take some time, I'm confident I can finish this project. Estimating the amount of development time needed at this time will be difficult though. So far I have managed to buy a used Z5 Compact for 250€ and am just wrapping up creating a custom git manifest file that references Sony, CyanogenMod (cm-13.0), AOSP (android-6.0.1_r24) and the necessary Ubuntu-specific repositories. I initially tried to simply sync the git repository found in these steps (https://wiki.ubuntu.com/Touch/Devices/minato) but after a week of trying to debug this process I figured out this repository is simply not up-to-date and it would be easier to use the associated manifest file as a template upon which to develop my own updated manifest file (approx. 7-8 hours in total so far). After this is finished I will move on to compiling a Sony's AOSP kernel patched with AppArmor 3.0. I think at that point I'll have an image together barring me compiling a bad kernel (fingers crossed).
I'll provide an update in a couple days.