Q6600ASUS P5Q-ECorsair 650TXWD 640Gb HdAntec 300
Either a 4850
with another when the prices come down.
PSU's that are included with the case are only good for recycling. 99% of the time they are low quality pieces of junk that will fry before being 75% loaded.
You can reuse your current RAM but if you want to upgrade, I would recomend 4Gb of DDR2 800