My chosen upgrade components

This is what I have considered to upgrade my computer in a short while some time next year. It would be good if I could get your opinions.

Australian Dollars

CPU
Intel P4 775 3.2GHZ HT EE - $315.00
Options:
AMD A64 939 3200+ (Venice) - $229.00

Motherboard
Gigabyte GA-81945P Pro - $177.00
Options:
Gigabyte GA-K8N-SLI - $148.00

Graphics
XFX Nvidia 128MB 6600 GT PCI-e $239.00 (with FarCry)

Memory
Kingston 2GB DDR2 (2x 1GB) - $245.00
Options:
Corsair 2GB DDR2 (2x 1GB) - $225.00

A few people havw said to me instead of the Intel core, get a AMD A64 3200+ with a Venice core…? They said it runs cooler and $100 cheaper (I have noticed that). I am also open to other motherboards models. My second options is really good and it’s also SLI. If someone could also explain to me why Kingston costs a bit more than Corsair, that would be good, saves me some money that I could use elsewhere.

Total cost: $976.00
Total cost (using options): $841.00