Intrusion prevention software

Hi,
I’m looking for intrusion prevention software. So far I found Entercept and it?s very impressive. I would like some feedback on it if you know it, and if you know other Intrusion prevention software that you can recommend I?d be happy to know about it. Anther question that comes in mind is, do I need IDS on top of it?

Thanks a lot.
Dfingold