basically intel p4 chips suck vs AMD64 chips but the new intel Core 2 duo chips majorly own everything on pure performance and price/performance.
so to answer your question get an intel Conroe chip, if you cant afford that get a intel allendale chip, if you can afford that then try very hard to afford it, if you still cant afford it then cry and get ripped off buying a slighty cheaper AMD x2 system
p.s. you posted in the wrong forum