The phenom II 955/965 are fine CPUs and will be good for several years.
As long as they are AM3 (not AM2+/3) motherboards and use DDR3 RAM they should be fine.
You really want 4GB RAM (2x2kit) and windows 7 64bit.
Case - look at Antec 200, 300, 900, 902, 1200 and Coolermaster Storm Scount, CM 690, HAF 922, HAF 932. I have no idea if you are looking for big or small, portable or not. All if the cases I listed have good airflow.
You dont have a graphics card listed. Without a graphics card you cant figure out what power supply you need.
ya but i think that the onboard graphics would suffice for my needs, so didn'y mention it!
and the cabinet is not meant to be portable, i mean it can be big enough on the fact that it should have proper cooling solutions.