Yeah get the 2500K, 6870 would be good or the 560 Ti, bump up the HDD to a 1TB or even 2TB if budget allows it (i would drop the blu-ray to get more out of my system for gaming), McAfee pfft gay I dont like it, forget the sound card just get a good surround system later on..
Edited: Forgot to say get a good cooler as well Hyper 212 would work but it also depends on the case size
if it's not pre-built, get a bigger hdd like 1tb samsung spinpoint f3 (or a 120 gb ssd + 1tb hdd combination if the budget allows). the more storage the better .
imo seperate sound card isn't necessary unless you really need it. most motherboards have decent sound hardware built in.
if your motherboard has p67 or z68 chipset, get a ram kit that has 2 4gb ddr3 ram @1600mhz.