I think the pikes are pretty variable in terms of personality, as the amphilophus can be as well. Like you said, some are calm, the majority are pretty aggressive, some are psycho. I have seen pikes which hid all day. I have had a large johanna who did not hide much, but mostly "chilled" and wasn't particularly active. My pikes that I currently have, are crazy active and devour anything that touches the water including pellets, begging for more when I stop dropping them in.
I think a wild Oscar sounds like the best fit of the options to me. Would be a nice addition.