DNS/IIS Server Addressing with NAT

I am running, but not sure if i am doing things as they should be done. I have a cisco router with 5 usable static ip’s mapped to various machines using nat to the 192.168.x.x space. At present my two dns servers and all IIS, FTP, and Mail servers are configured on the internal ip’s. Is this correct or should the dns servers be configured with the public ip’s. I’ve been trying to put in Active Directory and keep running into problems where the SRV records are not being created correctly (dynamic updates are enabled). If running DNS on the public ip’s, then could I set up a bridge connection to allow access to those machines from the 192.168 internal network?