I have a Gateway P2 dual booted with Windows XP & Linux Hat 9.0. I have another custom PC dual booted with Redhat 9 and Windows ME. Now on the Custom PC I have zonealarm 4.0 pro and multiproxy as my proxy server. Now on the Linux I have the one that comes with redhat 9 set as high security.

I have 2 LINKSYS 10/100 LAN CARDS 1 installed in each system. I have a Linksys Router as well with a built in firewall. I also have COMMVIEW packet sniffer on my computer. Is there any other hardware I can purchase to make my systems more secure?