As a self proclaimed silence freak here is what I would do in order...
Start with the CPU HS/F, the Zalman 7000ALCu makes a good match with the low thermals of the A64 3000+, it's also a very economical solution. If your motherboard has the ability to control CPU the CPU fan that is the method I would use.
For the PSU the Seasonic S12 is the best option. Since it sounds like your dealing with a relatively low power system the 330 watt S12 is plenty.
Next take a look at your GPU and MB chipset cooling, if either one of them are active you will want to replace them. For the GPU the Zalman VF-700 / 900 is the best active cooling solution. Alternatively if it's a lower power GPU you could opt for one of Zalman's passive units though they are a lot more work to install.
If you're MB chipset has active cooling you will want to replace with a passive solution, look to Zalman here also.
You didn?t mention what case you using or plan to use so I?ll leave out recommendations there.