How do i setup cPanel with 3 existing DNS servers that can be slaves

Just as the thread title says. I have 3 existing DNS servers that i would like to keep using but i ran into some issues already. For obvious performance reasons i really do not want to host DNS on the same server as the domains but i am willing to entertain the thought of doing it if that is the only way to get this work reliably. 1. Can i get cPanel to either show me the full complete DNS zone for a domain/user? 2. Can cPanel become master of existing DNS servers and how/where do i configure that? 3. Where are the zone files saved? thanks in advance