I would recommend a quadcore CPU of some kind. If you were going with an APU, I would like at something like the A8-5500/5600k. If you were going to go with a CPU, why not look at something like the Phenom II X4 965 and a 970 series MB? That would make more sense than the Athlon II X2 270.
Dual cores are not really enough for gaming anymore...they do ok, but they're starting to get overwhelmed by the newest generation of games.