I would put preference to faster processor initially. RAM prices fluctuate, but come down in the long run. Plus, I would actually go with either 6 or 12 GB as the channels are optimized for three banks per. If you go with 6, get three 2GB DIMMs. Then when you upgrade, all you’ll need is three more 2GB sticks for 12GB, or you could get another 12 with three 4GB sticks.
HandyGeek