Moser rears can be ordered with oem size 12mm short or long wheel studs, or slightly larger 1/2" short or long studs. 5/8" is also an option. Short studs generally won't be long enough to allow threads of the studs to stick through open faced wheel nuts, which is required in many classes of drag racing.
As far as strength of Moser wheel studs, I have not had a problem with them. There was a thread on here several months ago that several people did have some Moser wheel studs break. Bob