If you run Norton 360 you don't need any other realtime protection as it will most likely conflict with Norton. In addition, the best tune up utility is Tune Up Utilities, now at version 2009. Its one program that has literally everything and it even tells you what services to disable at your option in the initial setup. You don't need any other maintenance program and Vista's defrag should be disabled.
Even better the program is a fully functional 30 day trial if you want to try it out:
You can get it here:
TuneUp America - TuneUp Utilities 2009