I am conducting a study about server clusters and am trying to locate
IT Managers who are managing one of two particular types of clusters. 
I would like to contact them, either by phone or by email, to ask them
to participate in a legitimate market research study.  I am not
selling anything.  In fact, if they qualify and participate in the
study they will receive a free summary report and a small cash
honorarium.  All of their answers to my questions will remain
confidential and their identities and specific answers will not be
revealed to any third party.

My company has conducted these types of studies in the past.  At those
times, we found companies using the brute force method - namely we
purchased lists of IT Managers and called for hours until we found a
qualified candidate.  I am looking for one or more alternatives to
this approach that will be more time effective.

Here is a description of the two types of clusters.  We are looking to
survey about 30 customers for each type (60 total):

Type 1: From Sun Microsystems.  These clusters would have two or more
Sun Fire servers running the Solaris Operating System.  The servers
will be clustered together using Sun Cluster clustering software for
automated failover or parallel processing.

Type 2. From IBM.  These clusters would have two or more IBM eSeries
servers running the AIX operating system.  The servers would be
clustered together using IBM's HACMP cluster software for automated
failover and/or parallel processing.

I am looking for US companies or government agencies with one of the
above two configurations.  I am not interested in interviewing
colleges or universities.

In the past I have contacted some user groups.  However, I have found
that it takes a long time to go through all the channels of getting
approval to contact user group members.  Then, once we did, a single
group would only yield one or two surveys for many hours of work. 
Perhaps a national group would work?

I am a new user of Google Answers.  I am not sure if I placed this in
the right category.  Comments/suggestions are welcome as well as
answers.  Thanks for your time!