Hello,
with only 4 devices, you could use your workstation as the syslog server, but that depends on how your network is being monitored. In a 24x7 operations center, you would definitely need a dedicated server, but if you alone are responsible, logging to your workstation should be sufficient.
Not sure what you mean by metrics, but regarding configuring traps and events on the IPS, have a look at this document:
Configuring the Cisco Intrusion Prevention System Sensor Using the Command Line Interface 5.1
Configuring SNMP
http://www.cisco.com/en/US/products/hw/vpndevc/ps4077/products_configuration_guide_chapter09186a008055df87.html
HTH,
GNT