No - Oscar alone should be housed in a 55 gallon as a bare minimum, 75 would be better.
If you got rid of the Oscar the Cons and EBJD's "might" work, a mating pair of JD's will work in a 55 but an unbonded pair might cause some chaos.
I have read some of your other posts, I realize that you're one of the younger members here at MFK and your mother is limiting the number of tanks you can get. If a 55 Gallon is the largest tank you can get why not try to find a good stocking mix that will work for the long run instead of cramming what fish you want into it?
There are many other (larger) fish I would like to keep, however as a responsible fish keeper I don't try to house them because I cannot get the size of tanks they require. I believe that is the bane of all fish keepers here, there is always the limit of what we can keep and always another species that we would like to keep. Work with the tanks you have.