I have always chosen to keep my breeding plecos in species tanks. I do also have a few planted community tanks and I have had a pleco or two in such tanks. But these were mostly bristlenose. However, I had two H. contradens in with my altum angels. Also, when I acquired my breeding zebra group I had two wc males I had gotten years earlier and which had to be moved out. The only tank I could park those two zebras in was a 25 gal. tank which held a pair of discus. Those zebras lived in that tank for close to three years when they were moved in with my F1 zebras when I finally kept some for me.
I for sure would suggest you get the zebras, especially of the price is good. Moreover if two is all you need to house, a 10 gal. tank would be just fine, imo. A bit of sand, a piece of wood or two, a few caves and rocks and they will be happy as the proverbial pigs in poop.
I have always believed zebras are especially hard wired for flight. They have no dithers in the wild, and there are plenty of things which would happily eat them. This danger increases the shallower they are since birds, etc. can come into play. Basically, once they get beyond being very young, they soon learn to flee for cover at the first sign of movement. If they try to determine what made that movement they may get the answer from inside something. I have always approached my fish by keeping them on their own and providing them with a ton of cover as well as many caves. I figure the "happier" they are, the healthier and more inclined to spawn they will be.
Lastly, from a purely economic point of view. I am disinclined to put a fairly inexpensive fish in with my zebras. I would hate to cause illness or death due to the addition of a few dollar fish into a tank with zebras. But this is an issue everybody has to decide for themselves. For me it is easy. I have a dozen zebras plus recent fry in the breeder tank. I have another tank with 18 zebras, some of which will visit the NEC Convention in March. So I am not inclined to add other fish to tanks with that many zebras.
All of the above said, it is possible to keep zebras with other fish. It would be an issue of compatibility in terms of both behavior and parameters. I am not familiar with the other fish you mentioned, so I cannot help much in that respect. But a bit of reading seems to show they prefer cooler temps than zebras, appreciate plants, (zebras don't care) and none of my Hypan tanks have lights on them except for cleaning time.
https://www.scotcat.com/auchenipteridae ... s_orca.htm (Sorry but Scotcat has more info than I found here.) Temperament does not appear to be an issue. People who know the P. orca better should definitely chime in.
and here: The Aquaria of Bekateen (look for tank #22. "20 gal long Ninja wood cat tank").
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