Help A Confused Newbie!!!

There can be problems mixing the fish you list. First, a 75 isn't really big enough to add aother trigger--they tend to be territorial and will fight in smaller tanks. Eels can work, as long as there are plenty of hiding places so the eel can completely hide from the trigger--and you'll be happy with a fish you don't see often. I had a trigger and eel together with no problems, but the eel could go from one side of the tank to the other without ever coming out of the rock work. For lions--a small lion would work in a 75, but there can be problems with triggers nipping a lion's fins during feeding. Seldom aggression, just a trigger being a quick feeder. I did it, and the lion lost the tip of a fin two times--they healed, but you could tell those fins were a bit shorter for quite some time afterwards.

For puffers--can be a good mix. The biggest concern, once an appropriate sized puff is selected, is competition for food. Some puffs are really laid back and won't fight for food, so you have to make sure they get enough to eat. I currently have a striped burrfish in with my picasso trigger. The burr fish has his own cave, and he can be very aggressive about getting food--he will steal from the trigger--and I haven't had problems.

What is comes down to--any of the three will work as long as you pick appropriate sized animals and are willing to make sure they get enough to eat.