for gaming go for the 2500K. its the same die as the 2600K, just with HT disabled. most games dont make use of HT anyway.
Go for a good Z68 from Asus, Gigabyte, Asrock, or EVGA. There are others, but these are reliable boards (ive herd some bad stories about Asus as far as support is concerned).
For memory, some good 1600 MHz with CAS below 9 is good. Try Kingston, Gskill, Patriot and the like.
As for the CF thing, look at it like this. Say your CF set-up is being portrayed by a 454/4L80E set-up. Say the 4L80E is your motherboard. the info means 4 forward gears, Longitudinal (rear wheel drive), 800 ft lb torque max, electronically controlled. Now say your original card is the 454. You add some accessories (cam, lifters, polished/ported heads, headers, and the like) that adds the torque up to 975 torques. Now you want to keep your trans, so you limit the RPMs to make 800 torques at max RPM. You still have much of the same power. 1392 HP at 7500 (unlimited) and 990 HP at 6500 (limited). To tie the allegory back to the computer, the 7500 is the unlimited x16 bandwidth, and the 990 is the limited x8 bandwidth.
moral of the story is, you only loose about 10-15% of the performance of the cards. so 85% x2 is 170% of 1 card (just guessing at the numbers). YOu will be fine with x8/x8.
