i think a single dovii will be fine in a 180. i dono if u would want to put a pair in there though. i have my dovii in a 75 right now but im gona move it to a 125 in the next month. hes about 10 inches
really ? you have a 10 inch dovii in a 75 gallon? i don't know much but i do believe he won't grow to his full potenial and some parts of its body may become larger than others . not sure if the second ones true tho loool i keep my 4'' Jag in a 125 lol but if thats all you have it'll have to work lol
well everyone has different opinions on tank sizes. 180 will be just fine for any of the fish you asked about till they get 14" or so then you can upgrade. but really are any of the tanks we use big enough??? prolly not cause obviously the best scenario would be anything over 1000 gallons lol but not all of us can afford that. Im not gonna get into a debate over whats-what cause everyone is gonna do what they want either way. I have my umbee pair in a 180, dovii pair in 125, and jag pair in 75! they will all be upgraded as needed when the time comes.
so basically if whatever you get is small then you have a couple years in either 125 or 180 before needing to upgrade, but you will have to upgrade eventually. and if its permanent then i would agree that any of the parachromis with the eception of dovii will be fine in 180. good luck post some pics too