The 14” ornate will very possibly eat an 8” fire eel. When my endli was 7” it ate one of my 4” peacock bass that I had growing out with it.
Like others have said, the 125 won’t last the fire eel very long, but you’ll probably get a year out of it. I got my two biggest fire eels about two years ago at 4” long. They are now both near 28”. I have them and a third smaller one in my 220.
Keep an eye on the silver dollars because they can be fin nippers and bully other fish.