yeah the psu should be changed to the antec 750w why_me posted
the silverline is also really cheap right now
If you don't need the extra space go for the 320gb drive personally I don't any music, movies, pictures, etc. so my 500gb drive is filled with only 80gb of games OS and programs.
Later buy a vertex 3 pro (or other sf-2000 based SSD) and put games+OS+heavily used programs on it