wiltw, I think it will work IF he previsualizes the shot as a crop, keeping the subject further away from the lens.

I was going to recommend the 65, as it seems to be what you are looking for.
Your reasons are workable if you want a wider lens too, but from the original post it seems like you're giving yourself an unneeded hassle.

If you decide later you'd rather have the 50, you could sell the 65 and get the 50.