a 55 will be a waste of time with a ck and a pacu. a ck will easily get 18+" in a year and so will the pacu. a tank of 300+ gallons will be needed minimum for all the fish you have.
you have a pacu already lol, you might as well get a ck. The pacu will ultimately need more room than the ck will. And 9.99 is a decent price in the NE.