[tor-relays] Intrusion Prevention System Software - Snort or Suricata

[pa011]

One of my main ISP is going mad with the number of abuses he gets from my Exits (currently most on port 80). 
He asks me to install "Intrusion Prevention System Software" or shutting down the servers.
He personally recommends Snort or Suricata.

As far as I understand implementing such a software is not going together with Tor - am I right?
Somebody having same or any experience?

Thanks Paul