Ofcorz firestarter is more than enough.but lokkit makes u leave the thoughts about FW once it is configured
while firestarter is there always eating ur resources as it is a gui program.nevertheless it suffice the needs for many users.it is all ur wish which one to use from easy lokkit to shorewall FW config utility.and u may be knowing these all are scripts for controlling netfilter iptables,the FW in GNU/Linux.
Yes,cooltechietvm,u dont need any AV for Linux.u may have already read:
Note to new Linux users: No antivirus needed.
http://www.linux.com/articles/60208
also never login as root.use terminal and "su" for root access.if u want to start any gui apps from terminal use a X credentials wrapper called "sux".thus instead of "su" use "sux" and start any app.this is esp useful in konsole which prevents gui programs launched from it