Edit:
Scratch that - the Asus boards are too fussy with dual channel support when using 4 slots.
Decided to go for the following:
Abit Fatal1ty AN9 32X motherboard
Corsair TWIN2X 6400PRO DDR2 2048MB CL4 kit with EPP (4-4-4-12)
Athlon64 x2 5000+ AM2 CPU (when I can find someone with stock)
Cooler Master Sussurro 16dBA AM2 CPU fan