Alternate is good but expensive as fuck
PS: I think for just 800-900€ the i7 is the right thing you should get
CPU: Intel Core i7 920 ~220€
MB: Asus Rampage II GENE ~175€
RAM: 6GB (3x2GB Kit) OCZ Platinum Low Voltage (DDR3-1600 CL7) ~70€
PSU: Enermax Modu82+ 625W - 80€
HDD: Western Digital Caviar Blue (WD6400AAKS) 640GB ~50€
GPU: GeForce GTX 285 ~ 220€
Case: Antec Nine Hundred ~ 70€
Some shitty dvd-drive: 10€
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should be around 900€although there is no OS included like Vista.. maybe you can use the free Windows 7 RC kit which works fine till october 2010, and then you can buy a real copy.