Gary, which one would you recommend?

Gary,

 

I'm not Gary but I have the following AOA device:

 

 

Good for climb performance, glide, lift reserve comfort, descent speed, etc., etc.

 

I have used this tool along with other tools (altimeter, turn coordinator, VSI, attitude gyro, DG, compass, airspeed, etc) when appropriate and as needed - sometimes I look out the window as a cross check.