New gaming computer

Hello im searching for a new gaming computer. The computer will be used for games like Spore and new games in general, but mainly for Warhammer online.

Specc's

Processor: Intel Core 2 Quad Q9450 / 2.66GHz / FSB1333 / 12MB
Motherboard: Gigabyte GA-EG31M-S2 FSB1333 S-775
Memory: 4GB DDR II SDRAM PC2-6400
Graphic card: 1024MB GeF GTX 280 TV-Out PCI-E/DVI
Harddisk: 500GB 7200 RPM SATA2
Network card: 10/100/1000 Mbit netkort
Sound card: 7.1-kanals lyd
20x DVD +/- Dual Layer SATA
PC case ATX Miditower, 600W Low Noise Plazir PSU

Price: 1400$

My biggest concerns would be the PSU, I would like it to be able to handle upgrades n the future to come. Im not sure about the Motherboard neither.

I appreciate incoming replies.