Quality and Features. The DFI Lanparty is one of the best quality motherboards out there right now, and the absolute best for overclocking.
Aside from that, you're throwing away perfectly good advice. You ask for it, so you can't just pick and choose. Opteron 165 - 1.8GHz, Dual Core. Guaranteed (as much as it can be) to overclock to 2.6GHz to beat that X2 4800+ that you're getting. This, for half the price.
Other than that, the Corsair XMS. You're throwing away money with that. It neither overclocks, nor does it have extremely fast timings. Its the shiny version of Corsair ValueSelect. The G.Skill is one of the best quality memory DIMMs around, and the absolute best 2 x 1GB overclockers.
I mean...what're you doing? All the money saved you could put into Dual 7900GTs probably...