I'd def advise you go for a Sandybridge build - the processors are rediculously fast for the money and overclock nicely as well - When your on a tight budget its especially worth it, overclocking your processor is free performance. The other chips do clock nicely as well, but not compared to the sandybridges.
Also completely agree on the 4gb of Ram. Clearly having 3.2gb of ram is better than 2gb and as said before you can easily upgrade to more ram if you start at 4gb.
Also completely agree on the 4gb of Ram. Clearly having 3.2gb of ram is better than 2gb and as said before you can easily upgrade to more ram if you start at 4gb.