I recommend checking out the performance reviews of heatsinks at <A HREF="http://www.frostytech.com/" target="_new">http://www.frostytech.com/</A>. Tons of good info there, although they haven't yet reviewed the Volcano 9. Dan's Data also has a rather thorough review, which includes both of your possibilities:
<A HREF="http://www.dansdata.com/coolercomp.htm" target="_new">http://www.dansdata.com/coolercomp.htm</A>
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Armadillo<font color=orange>[</font color=orange><font color=green>TcC</font color=green><font color=orange>]</font color=orange> at Lanwar and MML