Well, the way I go for a conventional sound board that has prime mover and horn/bell is the ERR RailSounds Commander with the F3/F7 sound set. A smoke unit install will really depend on what's under those stacks, my guess is the E-Unit and battery holder is in the way and would have to be moved.
I'd seriously consider looking for a more modern F3 that already has sound and smoke, probably won't cost that much more and it'll certainly be a ton easier as far as labor is concerned!