Hi there, i have few question for the best suited DNS Setup for our compagny.

We have tree server located in montreal.
Two are running web services, one of them is only for dns ( home server ).

Two main server have Whm/Cpanel.
One run Cpanel Dns only.

Main server have 7 ips each
Dns server, only have 1

Let say we use domain xxx.com
Right now we have ns1/ns2/ns3/ns4 point to server1
ns5/ns6/ns7 point to server2

We have no Nameserver that point to our dns only server for now.
I'd like to advoid runing DNS Service on all of them, maybe having two slave one master would be fine. Question: What would be the best suited dns setup with my current config for best responding time and fast replication ?

Thank for everything.