Hi yeah as said the cichlids you mentioned are all American cichlids I imagine a mod will move this soon for you though.
All the fish you mentioned are really aggressive cichlids like some of the most aggressive common ones available. I dont think this mix would work in a 55g and the GT and JD would outgrow a 55g in the long term. If you can I would aim for a tank of 250 liters these size tanks are usually really well suited to mid sized cichlids. I think 4 or 3 cichlids depending on which ones would be a realistic aim, an important feature in tanks like this is dither fish these are fast fish that will distract the cichlids from each other but will be able to run away fast enough to avoid being bitten etc. Good fish for these roles are things like giant danios or tiger barbs in some cases columbian tetras work really well too.
Catfish wise I would stick to something like a trio of pim pictus catfish or hoplo catfish but nothing much smaller or less robust. Alternatively you could have some small species of plecs like bristlenoses or similar.
When it comes to cichlids its kind of down to personal preference but also an intelligent mix of species that need similar requirements and also those that are quite equally matched in levels of aggression - though this does often differ in individual fishes personalities. A few examples of cichlids you could consider would be things like Sajica, Honduran Red Point, Blue Acara, Rainbow Cichlids, Firemouths. You could consider jewels but they are really aggressive and often when they are kept in a community style tank they will kill other fish quite easily and readily. Other african cichlids that can work in these style tanks are things like Kribs and african butterfly cichlids. Just a few ideas for you
Hope thats helped
Wills