well 25/30 gal will work when they are small. but when they get larger they will have problem. go with a 55 gal. also make sure they both are around the same size. or one will eat the other. both won't go after another if you have enough hiding spots. i've had a dinosaur eel that went well with just about anything that didn't try to eat him for lunch. he never really bothered other much. so unless they both pick the same hideing spot then youare fine until they get bigger.
btw is it a striped peacock eels or a normal peacock eels. because striped will get bigger and out grow the othe eel. and one day make it lunch
The striped peacock eel and Senegal Bichir work well together although you will never see your peacock eel once he finds out he can dig in the gravel/sand.