CPU Cooler change

I'm in the process of trying to make my PC less noisy.
The first step would be to change the CPU Fan as well as the case fan.
On my P4 I currently have the retail FAN and wanted to go with the Zalman CNPS7000A which is apparenty very good and quiet ? Any other ideas ?
In my case (Kingwin), I currently have 3 80mm fans (2 In in the front and 1 out in the back). What type of Fans should I choose in order to still get a good air flow and low noise ?

thanks

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Asus P4C800-E Deluxe
P4 3.0GHz HT
1Gb Corsair XMS PC3200LLPT
ATI A-i-W Radeon 9800 Pro
WD 200Gb SATA
Lite-on IDE Combo Drive
Win XP Pro SP1