Dude when i had my arowana he was very easy to get off live food......Also i think Foster and smiths website only feed their fish pellets u could try to see if they send to you area ..
Also as for gars and knives
My uncle has a very large tank i think 850g's but could be wrong...He has 3 Florida Gars, 5 Silver Aro's and a few dats....
He refuses to throw a goldfish in that tank...
His method is to get a worm, longer pellets, shrimp, fish fellets, etc and just dangle them above the water with the occasionnal splash by letting the food touch the water and the fish hit it every time.... U could give that a shot