i'd say probably the 4200...it performs very well and has a good price/performance ratio
take the extra money the 4400 would cost and put it into system cooling
get a high quality hsf for the athlon and some good case fans, that geforce 4 will throw a lot of heat into your case
you'll have a nice fast stable system
don;t skimp on motherboard or powersupply either, i'd go with at least a name brand 350 watt..i.e antec/enermax
what motherboards are you considering?
i reccomend epox 8k3a/8k3a+
good ocing options, highly stable and tweakable
high quality pc2700 might be a better choice price/ performance wise than the 3000 or 3200
have fun building the system though..i always love that part