I've just built a Skyfun, which I think is the same kit as the Roo, but from a different supplier. I found some forum posts where people recommended Gorilla Glue for it, so I bought a small bottle on Ebay and tried it. It seems very strong, but was a bit tricky to use as it expands quite a lot as it sets. If I did it again I'd use 24-hour epoxy (5-minute won't give you enough working time to align the wings to the fuselage properly).
If you need to use cyano, one of the special foam-safe vareties should be fine, but try it on the box first if in any doubt. Normal cyano will definitely attack it.