Install more than one AV program, more than one software firewall on your machine?

Rubbish.

Multiple AV programs on a single machine will conflict and if you want layers of firewalls you should have a personal firewall on your PC and a hardware firewall between the pc and the net. Multiple antispyware yes, but they should provide complimentary coverage such as spyware blaster and MS antispyware (which is based on the same 'Giant' antispyware technology as Counterspy).