Gentlemen:

Here is a link to a very reasonably priced AOA.   I installed the indicator  adjacent to my airspeed indicator and, although I have no financial  interest in this company,  I can say that I am pleased with the product.  The vane is installed under the right wing  just about opposite the pitot tube on the left wing.

In my experience, once you have flown AOA, its hard to fly without it.

http://www.hciaviation.com/prod-aoa-a.shtml

Regards,  Bill Hogarty