Look at the Antec Neo Eco 520C power supply. Its an Antec 80+ rated for $5 more than the thermaltake you listed.
For gaming you would get better performance from an Athlon II x3 435 and upping the graphics card to a 5770. The 4850 is kind of weak for 1920x1080 resolution.
You could save money going with the Antec 200 case ($40).http://www.newegg.com/Product/Product.aspx?Item=N82E16811129070