Epcot: At entrance, in front of the big golf ball, they can add tink, or add butterflies to the pictures. Near bridge to France, can add balloons.
Regarding which photographer has what: just ask! We simply ask the not so busy photographers (no line waiting), and they can usually come up with something.
Problem in recent March break trip is that, there aren't many Photopass photographers around. Sometimes, it is hard to find one.