Max size? I would say with 7.5-8" wrists you should easily be able to wear 47mm PAMs and the Breitling Super Avenger (48mm), etc.
You're worried that something will look too big on those ham hocks?
Just kidding, I have a 7.5" wrist and I think the 47mm PAMs and the Super Avenger look silly on my. That's just my opinion, though. I know of guys with smaller wrists that wear Fiddys and Super Avengers.