Predator Tank

Question
I got a 250 gallon fish tank running for a month, I still haven't made up my mind in putting what in there yet, I was going to run three groups I thought of with you to see if these fish are compatible.

My three decisions
1 Managuense Cichlid (Jaguar Cichlid), 1 Peacock Bass, 1 Silver Arowana, 1 Lima Shovel-nosed Catfish

or

1 Managuense Cichlid (Jaguar Cichlid), 1 Peacock Bass, 2 Oscars

or

1 Managuense Cichlid (Jaguar Cichlid), 1 Peacock Bass, 2 Irridescent Sharks (Pangasius Sharks)


I plan on getting them at the same time and getting them when there all young and around the same size, I know a store that sells all these fish over where I live.  Can you tell me each one if they are good ideas or bad.

Answer
Hi Thomas,
The Managuense Cichlid is a very aggressive fish.  He will kill, and attack other fish.  He is a predatory fish, and so is the Peacock Bass.  The shovelnose will eat any fish he can fit into his mouth, but can be trained to eat pellets.  Never feed them feeder fish because these fish are full of disease, and you would introduce disease to your tank.
The Oscar certainly doesn't belong with these fish.  Oscars are far from being predatory, and do not fit into this category of fish.  They also need different water.  Oscars thrive in acidic to neutral water, whereas the jaguar cichlid, and Peacock need alkaline water, even though they can accept neutral, they do best in alkaline water.  The Arowana wouldn't last very long with the Jaguar, or Peacock Bass.  Irridescent sharks are gentle, and timid, they do not mix with the jaquar, and Peacock.
You cannot mix South American Cichlids with African Cichlids.  The Jaguar is just as wicked as the Jack Dempsey, and tries to kill every fish in sight.  Nothing will stop him even if you buy him small.  They only get worse as they grow older.  If you want to keep a predatory tank, you will have to go with predatory fish.   With predatory fish, be prepared to change your decor often so that they do not get too comfortable with their territory.  You will see when they start to become comfortable.  They can turn a tank into the valley of death, so observation is always the key.  A jaguar need 180 gallons of water all to himself if you want him to turn out to be the beautiful cichlid that he is.  This doesn't leave much room for other fish.  He will eat fish smaller than him, and attack fish because he dominates, and is wicked!  You will have to read up on him a little more to be sure you want to have this fish, and the Peacock Bass in your tank.  
You could however have a nice tank with less problems if you put two Oscars, and 2 irridescent sharks into your tank.  An arrowana could also be added.  One Oscar needs 60 gallons of water all to himself to be happy, and healthy...two Oscars 120 gallons of water.  You have enough room to house them, and you could also house 2 severums.  Just a thought..
It is up to you..
Hope this helps
Lynda