Most so-called 'AoA' indicators for light SEP aircraft are nothing of the sort. They rely on pitot and static pressure sesnsors, from which they 'deduce' AoA - usually on an overcomplicated display unit, to give the impression that they're worth the cost.
The aircraft I've flown with real AoA gauges displayed 'units' on a simple dial and had either an audio tone system (Buccaneer) or simple visual warning display (F-4).
I wouldn't recommend one of the current GA 'AoA' devices until someone has found a way of directly detecting actual difference between chord line and relative airflow and displaying it on a simple indicator.
The Russians have an excellent performance indicator in some of their aircraft - a combined 'g' meter and AoA gauge. Pull to whichever value is the more limiting and you're at your best turning performance!
Another of their very sensible instruments is a combined turn and slip and VSI - excellent for standby instrument work.