Sorry, I do not know of a very complete list. Best I know of is in the wikipedia article:

http://en.wikipedia.org/wiki/Fructooligosaccharide
"FOS is extracted from fruits and vegetables such as bananas, onions, chicory root, garlic, asparagus, barley, wheat, jícama, tomatoes, and leeks. The Jerusalem artichoke and its relative yacón have been found to have the highest concentrations of FOS of cultured plants."

Other than those, I found out it is in normal artichokes (argh! must be why they bother me despite no starch) and in nopal (which I was considering trying for reported healing properties, until discovering it has FOS).

I'm not sure if FOS is actually worse than starch; it does seem like I need to stay away from both.