The thing to consider with the aggressive fish listed is getting them to eat prepared foods can be a challenge. I would setup a q-tank, and use that to teach them to feed on prepared foods, while keeping your display disease free at the same time.
The combination of puffers, and lions can be difficult, as the puffers may nip at the lions fins. We discussed this in another thread, just thought I'd mention it again.
Depending on the species of puffers, most will eventually outgrow a 125. Something to consider for the long haul if you plan to keep the fish for it's lifetime.
I'd say start with the lion, as they really do not tend to be as aggressive eaters as the puffers. Let the lion settle in well before adding the puffer.
Have you considered adding an eel to the mix? There are a few that would do well with the mix. I would take a look at the SFE. Very easy to care for, easy to get to eat, and add a lot to the tank.