I have the core i5 2500k and an ASUS P8Z68-LE motherboard.
I personally use Corsair Vengeance 1866mhz Ram, but Asus ram compatibility is almost anything lol.
Hard Drive youd want a SATA lll 6gbps drive as minimum, but as the price of mechanical hard drives is so stupidly high, id suggest a small SSD and wait for mechanical drives to drop.
As you want 8gb RAM you will have to have a 64bit OS, so regardless of people experiences with the card, your only interested in 64bit users.
I personally prefer XFX cards and own an XFX 6950 2gb, can fault it at all, great solid card