Depending on what your upgrade plans are, you might consider going with 4GB of DDR3 RAM. If you are fairly confident that 4GB of DDR2 is all that you'll ever need for the life of the system, your build is fine. If you think you might need a RAM upgrade a year or two down the road, 4 more gigs of DDR2 is going to be more expensive than DDR3. As it stands now, high quality DDR2 and DDR3 RAM prices are near equal.