Well,you could if you get the 1055t...But imho,you would be best served by a 955 or 965 BE as they tend to beat the hexa-cores in most day to day apps (gaming) except for heavy multi thread applications (video transcoding or rendering) except when the hex is heavily oc'd. I'd wait on a hex until bulldozer hits the streets next year,and save your pennies in the mean time.
Definitely go w/ DDR3 as DDR2 is seriously on the way out right now. For instance,Asus's newest gen boards are strictly DDR3. I'm certain all others will follow quickly in line,if they aren't already there. No sense in buying dead socket ram either.