Cisco IOS Version audit (Vulnrable or Not?)

[Genjii <genjii () gmail com>]

I am looking for people to share there advise or any software that will 
allow me to achieve the following.

I would like to do an SNMP walk over all of my Cisco devices, to get the 
hardware and IOS version information.
With this information I would then like to audit each IOS version to see
   - Latest IOS image ave liable
   - Recommended IOS Image
   - Last IOS image that doesn't have any vulnerabilities
   - Then possibly an advanced check to see if my Cisco device supports 
the mimimum hardware requirements

The main difficulty here is an easy automated way to get this information.

Any suggesions?