Would agree with Victor, wykii are unpredictable with tank mates. I always try to grow them up with tank mates which they can't eat but in my experience when they get to 8" ish they start to harass others at night too much, even in 150 -200 gallon. Even plecs are not safe with their armour.
Like any cat, you could get a friendly one, not met a friendly wykii yet, they all seem to turn at some point, but here's hoping for you!
Mine is roughly 20" and puts up with quite a number of different tank mates including Jaguar cichlids, giraffe cats, silver shark, synos, culture cat, mystus, clarias, plecs, blackshark, variegated shark, limia shovelnose, knife fish, all good tank mates but only because of the foot print and 1500 gals like Victor said.
mine came from pier at 6" and was already nasty as their shop pet but they had her with motoro rays occassionally, but then she disagreed with any tank mates i have her in a six by two tank. No substrate - cos she just moved it all to one end. Took 2 more years to get to 1 8" feeding weekly on fillets of colle.
Moved her into the pond because I could better use the six foot tank and she was getting too big for it. Your 8*4*3 should be great and at that I would expect you to be able to get some success with tank mates, especially if your audio has its own territory(cave) but make sure you silicone it down, your wykii WILL move even very heavy rocks around your tank. Giant gourami another option as they have good body size but anything you do pick, just remember that you need something someone else would want if you had to move it on because your wykii fell out of love with it!
Keep us updated how your new devils doing.
