Hey Nat,
If you are not a tall person, get the 3 button jacket. Sometimes they are a little harder to locate. Also, suit jackets as well as sports jackets come in lengths of S (short) R (regular) L (long) ... examples: 38S, 42L, 44R If the short size is still too long, take it to an alterations person you trust. If you do not have one, get references from friends you know. This very skilled person can shorten it and no one can ever tell by looking at it but do note it will be somewhat pricey. I always have to have the arm lengths shortened. Pleated pants look best on the slender folks, where the flat front pants are great on slender as well as people with extra weight around their center mass.
Hope that helps.
Best Wishes!
RockOn