Savin up money for new hardware

Motherboard, CPU, and GFX card. That's all I need.

My motherboard is a Gigabyte 945PL-S3 and I heard it sux for dual core machines. Also have a Pentium D, and a GeForce 7300 GT.

What I want:
-No gfx lag when I'm in towns at MMO games
-Good for cell shaded graphics
-Good for graphics like Gears of War(just in case, but not necessary)
-Multitasking. Usually have 2 more apps running besides the game itself.
-Not too expensive. I'm a 14 yr old so this is gonna take more time the more expensive it is.
-Faster loading times

That's all there is to it but I might have forgotten something so....

Anyway, recommend a ram too just in case. I got 2 gigs but I believe there's more to it than gig size.

By the way, good for Vista too. Why? Well, just in case.XD