Ok damn guys....this isn't a see who pees farther contest...
I'm an Electronics Engineer as well.
I will say my favorite op amp to use is the LM358 but if I'm using one for multiple I/Os, I would use the LM3900.....However since I'm trying to tackle my original question.....using FFT to calculate a good audio analyzer output interfaced by the arduino...I know its possible and using the LM386 (Low power audio Amp) is what I have in mind.....
I hate op amps that need that negative supply i.e. 741
I just don't want negative gain I know that much so interfacing either amp via its non -inverting input (Rf / Ri) + 1 = Av (Gain)
now interfacing its output to the arduino via an analog Input and then interfacing that to maybe some LED drivers (Max7219s) to drive LED matrices......