What is best choice for cooling for this proc/mobo

[kenji808]

DFI LP UT nF4 SLI-D Socket 939 NVIDIA nForce4 SLI ATX AMD Motherboard

and AMD 64+ 3500 Venice Core

i dont know whats best for heatsink/fan

i was thinking about XP90 any other ideas?

plan to overclock, and computer usually stays on 24/7