Tomcat 6 binary in 64-bit

Could Tomcat 6 core binary be used in 64-bit Linux O/S ? which one of 64-bit
JDK 5 or 6 is recommended ? FYI the machine's processor is a 2 core Intel
with Intel 64 support, 16 GB DDR2 FB and 160BG SATA2 SAS.
And how many maximum heap -Xmx and PermGen space memory should be enough
with 120mb of war file with 50% of it are Jar libraries . Approximately with
100 concurent user sessions per machine  .

Thank you in advance