Haha nice, looks like you got it all figured out. I actually do have a piranha tank.. A Peruvian high back rhom that I grew out from a baby. Currently housed with a school of exodons in a heavily planted tank with driftwood. Right now it's only 5-6" and grows really slowly lol. I'll make a post about it.
Wolves/ATF/piranha.. Looks like you have a fascination for teeth like me. Haha
My future plans is probably a giant monster setup primarily for possibly high end bd stingrays with a high end red, snow or albino aro along with my characins. Has to be big enough that I can have two dividers that seperate them during pregnancies. Other than that, I want a dedicated driftwood/hard scaled tank for a beastly aimara with green neons. Maybe a couple more tanks for nurseries and quarantine tanks. This all comes down to when I do my planning to renovation of the basement to get all the plumbing structured and setup. I currently have too many tanks spread across which is taking up too much time for me to maintain. I have so much work to do on the regular and also a gf that's not the most supportive of the hobby. LOL