Forgot to mention Cinctas can be aggressive there shuldn't be much of a problem with large cichla
As for diet pikes will usualy many different things and alot of it try Shrimp, Krill, fish fillets, crickets, worms and like every fish pellets are all ways good if you can get the pike to eat them
They will adapt to most water types but like soft acidic water
For price it all depends on size and the location there being sold at theres also color varients the most common is the green cincta which will sell for aorund $30-$60 to give you a rough estimate
Ohhh and if you haven't seen it theres a sticky called identification thread which has alot of great pike pics of most of the pikes i listed