This has all been hashed out before (some interesting threads, those!)
but here is my 2 cents:

AOA can be derived from pressure differential, best way would be to
have sensor ports in both wings (enough to be redundant and avoid yaw
problems. Nose might also work, but it's the wing you care about,
really.

AOA is really only needed at high angles: Stall, Min Sink, L/D max,
recommended approach speed. Since these speeds vary with weight and
bank angle, AOA is better than airspeed. So to keep it simple, with
gear up show min sink (for thermalling) tied to flap setting, and
maybe have an index at L/D max (not really used that often). Gear
down, show desired approach speed, with warning approaching stall.

I think the military chevrons and doughnut indicator would work just
fine: On-speed (desired AOA) when center g(green) circle is lit.
Slightly slow when circle and lower up (red) chevron are both lit.
Slow when only red up chevron is lit, slightly fast when circle and
upper down (yellow) chevron is lit, and fast when only down chevron is
lit.

Electronics would need input from gear and flaps, if present, of
course.

Easy to see if on top of panel.

Kirk