I5 build suggestion?

Hi,

APPROXIMATE PURCHASE DATE: I want to build a new computer around mid-november
BUDGET RANGE: 1000CA$

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: gaming, downloading music/movies stuff like that, surfing the internet, watching movies

PARTS NOT REQUIRED: keyboard, mouse, monitor, speakers, OS

PREFERRED WEBSITE(S) FOR PARTS: newegg.ca, ncix.com
COUNTRY OF ORIGIN: Canada, Quebec, Montreal

PARTS PREFERENCES: Friendly overclockable components.

OVERCLOCKING: Yes
SLI OR CROSSFIRE: A no/maybe I know the i5 build isn't a top double GPU platform.

MONITOR RESOLUTION: 1920x1080 or 1920x1200

ADDITIONAL COMMENTS: I play a lot FPS (coming MW2, etc.)
I am wondering if the i7-920 has a better price/perfomance value because of its overclockability.In my case, a few extra buck for (example) a SLI/XFX configuration, extra 2Gb and higher clock frequency would be a better option for me.

asus p55 pro

Intel Core i5 750

G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600

wetern digital 640gb

CORSAIR 750 watt

XFX 5850

SAMSUNG Black 22X DVD Burner Black SATA Model SH-S223B - OEM

COOLER MASTER 690

should be round $1000

Do you think that there'll be a lot of improvement worthing the waiting time if I wait after X-mas. I recently heard that it is the best moment to buy a computer... Just thinking at the "GTX 300" or any new 5xxx model supposed to come really soon.