I currently own a 9mm commander version of the M5. I have also owned a government model in 45acp. Both are excellent pistols. I have also heard the P18-9 mags will work, but new Bul Transmark mags are available from All American Sales in Piggot AR.
I will measur the width in a few minutes and post it here.
The grip is about the same size as a Glock in my opinion.
Live to shoot, shoot to live!