IDS?

The place i work at now have never been connected to the internet. Now they decided to g4et online. I have come up with a couple of security policies and a list of firewalls to implent. y question is i am currently looking into Intrusion Detection System, and I was wondering do anybody have any good IDS Vendors they worked with of heard about. Something the detects at the host and network level. Any help would be appreciated.