RE: Adjustable Stab
You will have maximum flexibility with adjusters on both wing and stab, but you also increase the installation and trimming complexity when you do that.
I prefer adjusters on the wing only. The stab is normally fixed in my planes for two reasons: these are smaller and easier to get perfect than wings and a fixed stab installation is much much lighter than adjustable stabs. You can also include that a fixed stab produces a far stronger tail group than adjustable will. There are no negatives in my view.
It does require that you get the stab in right to begin with, and that is the main assumption.
MattK