Hello, Amazons a puffers are one of the few species of puffer that is fresh water. Scats are brackish, and the snow flake eel is salt water. So that set up wont work. Possibly a peacock eel if you want a eel, your makin me think about it now lol. I just upgraded my 10 and am getting a 29 gal. I decided that i am going to go with 2 amazons, a pictus cat (possibly rainbow shark, or both), a ram, and my clown pleco that i already have. I have read that most fish without long flowing fins will do fine with Amazons (ie. Mollies,rams,platys), but there is always that possillity that they can snap. If you do go with a amazon (or any puffer) make sure you have a heavily planted tank with lots of places for them to explore. Amazons also perfer to be in groups, prob 2-3 for a 29. Also it is very hard to find amazons at least were i live. I have searched all over NY and couldnt find any.
im still on the hunt though. Thats just what ive found on amazons in my searches. Hopefully i helped you with some possible tank mates and tank layout