Ok, after your great help, here in this forum, I think I'm ready to order my new PC. I just wanna be sure, that everything is perfectly compatible. So here we go:
CPU: Intel Core i5-2500 Box, LGA1155
Motherboard: Gigabyte GA-Z68P-DS3, Intel Z68, ATX
CPU Cooler: none
Memory: 8GB-Kit Corsair XMS3 PC3-12800U CL9
Power Supply: Corsair GS Series, 700 Watt
GPU: Sapphire HD6870 1G GDDR5 PCI-E DL-DVI-I+SL-DVI-D / HDMI / DP
Hard Drive: Seagate Barracuda 7200 500GB SATA 6GB's
DVD: ASUS DRW-24B3ST Retail SATA schwarz Nero 9.0
Case: Antec Two Hundred V2, ATX
So, if you don't find any flaws, I'm gonna order this rig for 780 Euro including Win7 HP.
Again, thanks for all your help!
Xamael