I just built a new system with the same chip. I was having temp and power problems with my old rig so I went with the following:
AMD Athallon 64Fx-53
Asus A8V Deluxe VIA K8T800 Pro Chipset ATX AMD MB
1 Gig of OCZ 3500 unbuffered Ram
2 Western Digital 74 Gig Raptors in Raid 1
DVD ASUS 16X DVD
CPU FAN SPIRE|SP703C3-1 KK3 AMD
Cooler Master Wave Master Case with 500 watt power supply.
M-Audio Revolution sound card.
I'm using AMD's Cool and Quiet on the MoBo and so far in my un-air conditioned computer room, I've been getting the following temps on a consistent basis:
CPU 42* - 47* Celcius at idle. 53* - 55* Celcius under load
I think that anything to the high 50's would be fine since the kickout temp is 70* Celcius.
Hope this helps.
If you don't stand for something, you'll fall for anything.