A 50 gal is a reasonable size tank for a pair of blue acaras, and dither fish (non-cichlids large enough, and fast enough not to get eaten)
Some medium size South American tetras, would be an example of good dither fish.
As an option, you could keep a trio of fire mouths, with some non-cichlid dither fish, such as the above tetras, of large live bearers, temporarily until the FMs out grow the tank, and you upgrade.
If you want more than 1 species of the cichlids you mention above, in the same tank, you need to upgrade into one at least 6ft long and over 100 gallons.
Even then, GTs and blue acaras should not be kept together in a 6ft tank, same goes for GTs and JDs, they are not often good together because they look too much alike (the blue spangles) because cichlids that look alike, see each others as competitors, even in 6 ft tanks, unless they have the ability to divide it 50/50.
Non-cichlids are usually ignored, unless bite size.