i'm 5' 5", 150 lbs (not fat, muscle) and i have broad shoulders so i went with large jacket medium pants.
i have a pair or large sessions pants that are close to the same size as the medium saga, and they fit perfectly, pretty baggy but not too crazy. stoked on the jacket though, kinda worried it might be too big but i can always return.
on a side note, i think the blue saga logo on the murda mystery pants looks sick.... but i guess i'm the only one who thinks that...