Pretty sure keeping & selling gamefish as 'pets' is illegal in NJ - mostly because of size limits and unless those pike are 24" you may not want to advertise you have them(careful -the FBI will track you down via your IP address

)
Panfish like sunnies, crappies, perch, catfish are all fine though along with any minnows/carp/suckers. Yeah , I know, those aren't the 'cool' fish but rules are rules. My brother used to feed goldfish to his bass during the winter months when getting food(minnows/sunnies) 'naturally' wasn't easy. It was fun for a few years but eventually the novelty wears off and you just end up releasing them which is technically illegal as well(need a permit).