SIMS - Prelude vs OSSIM vs OpenSIMS, with Nagios and remote logging too

Hi,

Briefly, my question: does anyone here know the best way to implement
all of these (Integrity Checks, Servers Monitoring and Remote Logging)
in a mixed environment (UNIX/Windows), everything being open-source ?

Details of the question:

I am looking for open-source products to secure our network and
servers, which are a mix of Windows/Linux/AIX. I am looknig for some
help in deciding what products to implement.

1- I want to begin by implementing an integrity checker. I am looking
at Samhain and Osiris. Samhain seems better, but since it does not
support Windows, I will probably use Osiris.

2- I want to run Nagios on my servers for monitoring

3- I want to setup my UNIX and Windows servers with remote logging. For
the UNIX/Linux servers, I would do remote syslogging to a syslog server
such as Syslog-ng or Rsyslog. For the Windows servers, I would also
setup a remote logging to that same syslog server, with a client tool
such as Winsyslog.

4- On top of that, I would like to implement a SIMS. I know of 3
open-source SIMS: Prelude, OSSIM and OpenSIMS. Is one better than the
other with my mixed environment?

5- Would a Change Management Solution like Radmind on top of all that
be compatible worthwile, or it would mainly be redundant ?

So my question again: does anyone here know the best way to implement
all of these (Integrity Checks, Servers Monitoring and remote Logging)
in a mixed environment (UNIX/Windows), everything being open-source ?

Thank you.