Slow growing they are, which would take care of a 75g being too small for a pair for at least a couple of yrs. And aggressive is one of the qualities he's looking for.
They're conspecific aggressive, not fun "glass banging" aggressive. They just like to beat the crap out of each other when you're not looking.
How would you plan on pairing them off? Have you ever raised this species and gotten a successful pair out of it, or are you just going by what you've read?