I once had a community 135 gallon that housed an albino oscar, buttikoferi, texas, jaguar, convict, and green terror. I introduced all of them when they were about 1 to 2 inches with the exception of the jag. I put a 1 to 2 inch jag in there when the oscar and buttikoferi were about 6 inches, and within 4 months that jag had almost caught up in size! I eventually gave them all away because I had hopes for a pair of something else and knew they all wouldnt work out long term.
Moral of the story is jags are beastly and really don't match well with oscars unless there is a drastic size difference with the jag being smaller.
I really want to see the 1000G tank. You could go snokeling in that thing!