Help required regarding graduate admission

Hi all,
I have recently graduated as a computer software engineer from the
National university of sciences and technology, Pakistan. I want to
pursue graduate studies (Masters) but i am quite undecided about
which universities to choose. I am applying for Fall 2005 and i have
to be very precise in university selection so that i am able to get
admission in one of them. My CGPA is 3.34, i have not taken the GRE
yet. I am going to take both GRE and TOEFL by the end of November
2004. I haven't done very good preparation for GRE so my score wont be
good. I was declared best in Research and Development in my batch,
co-authored two research publications, won the first prize in a
national software competition, participated in Computer Society
International Design Competition (CSIDC) 2004 and i am very determined
to take on further studies. I have one year of experience working at
PTCL. I have looked up different universities, my core area of
interest is computer networks and network security. My final year
project was an Intrusion detection system which i did in collaboration
with the Pakistan Telecom giant i.e Pakistan Telecommunication Company
Limited. The universities i have checked out are

Purdue University
Georgia Tech
University of Texas, Austin
University of California, Urbana Champaign

Please advise me if i am too optimistic in my university selection.
Which universities should i apply to (considering my profile) so that
i can be almost sure that i would get admission in one of them.Thanks

Regards