I could see a 180 being a nice grow out tank, for that crew, until they are just pre adult.
But as adults (looking across at my 180 at the moment) maybe 3 Uaru, and e seveum in one.
But another 180 for the pair of parrots (that is, if by parrot species you mean the real ones (Hoplarchus psittacus)) they can be quite aggressive, and need territory. once mature.
To combine all the ones I mention above, maybe a 300 gal.
I would also "not" put the Vieja, with any of the above, on geographic and water parameter preference alone, but also its aggression level.