IMHO, Celidos will be best kept VERY crowded, the tank that Felipe has his in is stacked top to bottom with fish (anyone that has been can attest to that). . . they are mean SOB's and will kill each other without a reason LOL I have never kept them, price prohibitive for me (plus we never tried to get any when we were there) but, I think that you will find that most people end up with one. Not that I am trying to sway you either way, just my line of thinking. Plus, Vitatta are gentle giants of the pike world. . . food for thought 
Ray

Ray