Can an NJ resident with a handgun purchase permit buy a handgun or conduct a trade/transfer at an FFL in NY or does the handgun need to be sent from the NY FFL to a NJ FFL to perform the transfer?

Federal law - the final transfer of a handgun from FFL to you has to occur in your state of residence.

Long guns can be purchased at FFL in another state as long as the laws of BOTH the "foreign" state and your state of residency are followed.

Thanks, I appreciate the response.