I'm not sure if there is any overview on the web with all dialogues, i guess not...
Well technically these conversations are not very well implemented, they work like speaking one-time-traps on the map (because party members can't really speak).
If you step now in such a trap then the party will be checked for a coulpe of possible member combinations (mostly about 3) and if any suitable combination has been found the corresponding conversation will be played and the trigger removed afterwards - thus no chance again even if you come along another time with different party members as before.
So this sadly has some chronical weaknesses, however mods may partially provide some alleviation.