The website you picked is seriously deficient in CPU Cooler and PSU choices. Case choices also seem very limited.
But from within the choices available and keeping your budget in mind look over these choices.
MB: Gigabyte GA-EP45-UD3L 375
CPU: Intel Core 2 Duo E7400 2.8GHz 421
-(alternate CPU): Intel Core 2 Quad Q8200 2.33GHz 597
CPU Cooler: ZALMAN CNPS9500AT 138
RAM: 4GB Corsair TWIN2X4096-6400C5DHX XMS2-6400 2X2GB DDR2 239
DVD Burner: LG 22x SATA GH22NS40RBBB 63 (OEM w/o software)
HDD: WD WD6400AAKS WD CAVIAR (Blue) 640GB SATA 244
Video Card: XFX HD-487A-YDDC HD4870 PCI-E 512MB DDR5 850
-(alternate video card): Asus EAH4870/HTDI/512 HD4870 PCI-E 512MB DDR5 760
Case: Antec NINE HUNDRED 414
Power Supply: Antec EA-500 EC EarthWatts PSU 500W 275
about 3019 LTL
For an AMD build I was looking for :
Gigabyte GA-MA790X-UD4 motherboard and AMD Phenom II X3 720 Black Edition CPU but both were missing.
The best options I could find were Asus M3A78-T (790GX motherboard) 435 and Phenom II X4 920 677
SILENT KNIGHT AL Asus SILENT KNIGHT AL, All Copper, Ultra Cooling for Dual-Core CPU, socket775/AM2/754/939/940, Heat Pipes/ Max Airflow 45.6 CFM/25 dBA 134,83 Lt
TOTAL: 3.009,54 Lt
Not sure about the psu(because CPU changed to q9400) (more than 500W is chieftec, Antec NEOpower, (Nexus and Zalman would be out of budget)), CPU cooler (any opinions on it ?). Originaly thought about a UD3P mobo but seems it's not available anyomre in here ;(