sorry to break your bubble but if you want your kids to be able to play halo 2 your going to have to buy them an xbox it probably won't ever come out for pc.
it would be helpful if post how much each individual part costs then we would know if changing X to Z would save money or no without having to go check prices.
it would be worth upgrading to socket 939 because the A64 3000 for 754 actualy performs much lower than
im bored so here is a computer well worth the $65 difference
you really need to stay away from the GeForce fx line
some $50 case with psu
Athlon 64 3000+ s939 $150
ECS KN1 extreme w/integrated wireless G (is backwards compatable with wireless b) $130
MSI GeForce 6600gt PCIe $185
corsiar value select 2x 512 $99
hitachi 80gig sata II HDD $61
NEC 3520-A DVD/RW $60
http://graphics.tomshardware.com/graphi ... index.html
this is a set of benchmerks for how well different graphics cards perform it lacks the 9600 but just look at the GeForce PCX 5750 it is about as powerful. you will notice in some benchmarks such as the doom 3 ones the 6600 gt will get almost 4x as high of a score.
PS: you should look at the massive package that comes with the MSI 6600gt