daaarn ul need like 300gal for an arowana! they look incredible tho. how big is ur current tank?
and no, they arent compatible. some aquarists are very lucky and get south american and africans and they somehow DONT shred eachother, due to personalities, but they need different feeds & parameters & temps.... its just not sensible OR kind to the fish.
sounds like u have:
elec yellow lab, red zebra, powder blue cichlid, rusty cichlid, bumblebee and fuelleborni or cobalt zebra (black and blue vertical striped one) but thats only on assumption