Welcome .
Your husband will be mad before you are through !
You will need a bigger tank .
The Sterbai and betta are the only fish that may handle the heat needed for disc .
I keep German rams and clown loaches with my disc .
I am the ram guy and they need the heat also ..
Rummy nose ,Cardinal tetras ,Sterbai cories ,German rams ,and clown loaches are the most commonly and properly kept fish with disc as I understand .
Many and I mean many never have any other fish with their disc …
I would not add disc to your tank as it exist now ..
Again Welcome .