At small sizes RTM’s are in my opinion the most agressive of the Parachromis. Dovii eventually get more agressive as they grow larger. Becoming arguably the most agressive Cichlid there is. Mostly because of their size, there isn’t anything in the cichlid world that can stand up to a 30inch Dovii.
A pair of Dovii require a much larger tanks I suggest a 8x4x3 or larger.
As long as the 160 is 6ft long yes, I think you have a good chance of keeping a pair of RTM. Could be a lovely tank, I love RTM’s.
Again the best way to get a pair is to get 5 or 6 little ones and let it pair naturally and rehome the rest.