Heres my pacu. Hes in a tank with 2 piranha and a common pleco.
Here are my oscars. I also have an albino pleco and an angelfish in this tank.
Keep in mind these are two seperate tanks.
sell the pacus ( cause an average aquarist wont have a tank big enough for a full growin pacu besides some ) and the pirhnas, and stick the oscars in the 150 and set the 55 up around your angelfish.
Heres some more photos I just uploaded of my fish.
About a month or so after we had the pacu, the piranha bit a good chunk out of his face. You cant see it very well in this picture, but I tried to get a good shot of it.
Heres my plecos.