Actually I'd like to propose an idea:
Why not keep the cap at 100, but re-set it to 0 annually so everybody start afresh each year?
That's kinda like what they do with tennis ATP tour right? Each player start with 0 and gathers points as they win tournaments and and at the end of the year they crown the winner. I think they also do the same thing with the PGA tour if I'm not mistaken.
That way new posters also have a chance at posting better and getting somewhere too instead of same old same old posters with 100 Rep.
Just a thought.