If you're not OCing, the stock HSF that you have will do fine.
If you're not comfortable, you can get a better HSF, like the Thermaltake BigTyphoon or the freezer pro. They'll give great results and will be more than enough for stock, and give you great results for OCing... and cost a lot less than watercooling
AMD Athlon XP 2800+ (Barton) @ 200x10.5=2100MHz | Asus A7N8X Deluxe | Corsair 2xCMX512-3200C2PT @ 2.5-3-3-8 | MSI GeForce FX 5600 128MB | Hitachi Deskstar T7K250 160GB SATA II | Antec NeoPower 480W | Creative SoundBlaster X-Fi Fatal1ty
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