I have the longwaisted problem too. Are you looking for bike jerseys or tri tops? From what I've seen, unfortunately, it seems like tri tops have a tendency to be even shorter (that is, they are cut shorter by design, but they seem to run shorter even given that).

I have found Castelli, Gore and Sportful to fit well in the length department (all of these fit me well generally too). PI & Shebeest tend to be too short for me. Sugoi is kind of in the middle. I have tried on Sheila Moon stuff (haven't quite been moved to buy any), and it seems to be longer too. If you are inclined to try it (and can stomach the prints ), I would say it runs at least a size larger than most cycling apparel, so consider sizing down.