Security Solution

Hello,

I've been meaning to do a complete system reinstall, and I would like to take that occasion to change the security programms I'm currently running on my computer. However, I'm not overly familiar with this part of the computer world so I would like to ask for some advice on that.
I am currently running :
- Norton Antivirus as an antivrius.
- Windows Firewall + Router hardware firewall as firewall.
- Spybot and Adaware on a more or less regular basis for malware.

I would like to know if someone could recommend me a programm or a group of programms that would perform the same tasks more efficiently. I don't mind paying for a programm if the price is reasonnable, but I would of course prefer a free solution.
As of now, the configuration of computer is as follows :
Core 2 duo 6600
2Go DDR2
Asus P5N 32
GeForece 8800 GTS 320MB
Creative Audiogy
Windows XP Pro

I thank you in advance for any advice you may be able to provide me.