If you could squeeze just a lil more from your tight budget, go for the Radeon 4890 1GB GDDR5 instead of the GTX 260 video card,
not only its so much faster and has a Shader 4.1 and DX10.1 support but in the long run, you'll be playing very demanding games
that can be more enjoyable to play when using high end video cards. The price margin if you would compare these two its only $15-20.
IMO, the amount of gaming experience and enjoyment you would get for the $20 difference is way way more than gaming with a GTX 260 video card and I GUARANTEE YOU THAT!.
If your budget is still up for another extra 1GB or RAM, then you'll have a gaming rig where you can play the latest demanding games in a very long time.
-- In addition, go for the Phenom X2 550 BE procie, it is way more faster then the X2 6000. (20 percent faster!) and you can OC the
X2 550 way more than the X2 6000 procie could handle.
Hope this helps.