I would like suggestions on building a computer. I have some parts from my old computer that I will use. I have $375 to $400 to spend on a motherboard, 1 gb of ram, cpu, & case. I was looking at mobile chips. I have a sk7 heatsink which I can replace if needed. I am open to overclocking. I want to go as fast as I can and stay within my budget, or close to. Would an 754 pin Athlon 64 be faster than an overclocked xp mobile chip?