Stocking Suggestions For 55G

[FlakeyBiscuit3.14]

So a friend is getting rid of their 55G, and is giving it away for free, so how could I pass that up??
 
Anyway, before I buy ANYTHING for it I want to make a general decision about what type of fish to get for it.
 
So far my 29G tropical community tank has been going well, but I'm not sure if I want another tank with the same kinds of fish. I'm kind of thinking of trying something different.
 
I was thinking cichlids, since I have well water and the pH is naturally 8.3... but in general I don't think they're as pretty as a lot of the community fish and I feel like they would be harder to take care of.
 
Catfish are my favorites, such as corydoras and synodontis, and I also really love invertebrates, so if I could have some of those that'd be cool.
 
Any suggestions would be awesome. I've never imagined having a tank this big before, as it had pretty much been out of the cards for me. What are your favorites that you have kept? Which were more difficult that others?

 

[fluttermoth]

I haven't kept them myself, as my water is super soft, but what about rainbow fish? There are a few different species, most of which prefer harder water, and they can be spectacular when coloured up and mature (they often don't look much in shop tanks).

A shoal of boesemani in a planted 55g would look awesome, and I they're not difficult to keep.

 

[FlakeyBiscuit3.14]

Oooh those boesemani are really pretty!!! And I could still keep some community fish with them too They seem pretty expensive for a school, but I will definitely keep them in mind.

 

[Mark Z.]

I have a 48 gallon with a school of Congo tetras. I love them!

 

[Sickbound]

Well, if you like catfish, I have a couple suggestions...
 
Flagtail hoplos (Dianema urostriatum) are some of my favorite community catfish. Beautiful tails, and they have an interesting body shape. They get about 3.5-4", and do best in shoals. Super easy to take care of. They are technically bottom-feeders, but will come up to the surface and sift through floating plants to find food. They are active swimmers, but will also rest on anything that looks remotely comfortable. Mine balance on the roots of floating plants, and float (seemingly completely still) in the water column. They also lay on top of eachother like jenga blocks. 6 to 8 should do just fine in a 55 gallon, plus you could add other fish for the mid and/or top levels.
 
Raphael catfish are another one of my favorite catfish. The striped Raphael's average size is 7", but a pair at my lfs are greater than 10". The spotted Raphael stays a bit smaller, more like 6" I think.  It will take them a while to get that big, as they also live a long time, Some live to be over 15 (!). They are extremely peaceful to anything that wont fit in their mouth, and are really interesting to watch. It would probably be best to stick to one of these guys in a 55 gallon.
 
As for inverts, amano shrimp are really interesting freshwater shrimp. They are somewhat larger than the average freshwater shrimps, are hardy (as far as inverts are concerned), and very active. Fun to watch in groups, especially if they are provided plenty of materials to climb on like driftwood. Another one of my favorite freshwater invertebrates is the blue wood shrimp (Atya gabonensis). They are filter shrimp, much like the common bamboo shrimp. They get to a maximum size of 6", and have these gnarly looking gripper claws, which look like they could do damage (but they don't). They are extremely peaceful and shy inverts, but are fascinatingly big and strange looking, and also captivating to watch when they show themselves.