Ryan, wonderful rendering with the M-M! It is an amazing camera ISO 10,000 is very good also.
Ron, excellent images of the boy! Great colors and lighting. I have noticed your recent shots are just improving all the time!
Adam, the 50AA would be great, but have you considered the 50 Nocti f/1.0, as it is lighter, smaller and half the price. If this lens does not agree with your style, it is very easily sold and maybe then exchanged for the 0.95, or something else. I think here you would have a great contrast between the two styles of lenses, and possibly fitting easily within your budget.
I must admit I was so close on getting the 0.95 Nocti, but jumped when f/1.0 came up, and I have no intention in upsizing...yet
ISO 10,000 is very good also.