For whatever reason, I always cast Nan Bacco as looking and sounding like Future Janeway Despite there really being no connection there.
Oh, Soso is good casting for T'ryssa.
I've always thought that mental image (because I've had it myself, and tried to get away from it since I've seen KRAD get frustrated about that particular imagery) came from the cover - there is something about the posing, stance, and the hair of the image on the cover of Articles of the Federation that gives off the 'Admiral Janeway' appearance to me.
After seeing The Force Awakens, though, I think Carrie Fisher might be a good fit for President Bacco. Especially considering all the interviews she's had plus her tweets.