Im not quite picking up why anyone would purchase a mobile xp and an nforce2 board right now. For about the same money you can get an Athlon64 3000+NC and an Nforce3 board. Also, regardless of overclocking or not, a video card is not a high priority unless you are building your system for GAMING. The video card will not bottleneck the processor.
In any event, when building a system, the priority list should be:
1. Motherboard - because you can always upgrade to a better CPU to fit in the current socket
2. CPU - Gaming, editting, etc? Regardless, the CPU is basis of a system.
3. Memory - lets all remember that memory is easily upgradable, but can create bottlenecks.
4. Video Card - being that not all computers are built for gaming, a video card is more less of a nice addition rather than a top Priority. As you can tell, im not much of a gamer, i play BHD all the time, but thats really about it. Although, i have played just about every game on my PC. My graphics may not be as good as yours, but i still kill the bad guy the same way....