VGA Upgrade with PhysX feature

[eszaqsc]

Need help/advice. I want to upgrade my EAX1650Pro vga into something that can play smooth on at least 1360x768 resolution and i want the PhysX feature on it, i dont need the SLI feature yet because i'm still using my old mobo ASUS M2NPV-VM (i think it still use pci-e x16 ver.1.0); m processor is AMD Athlon 64 X2 3800+ using corsair twinX (2x512mb) ddr2 800MHz (i intend to add more 2x1gb), My PSU is Acbel 400w, i'm using 1xSATA HDD 7200rpm and 2xSATA Green (WD Green) and 2xDVD-RW, i'm confuse at GT440 and GTS450, what should i choose? or is there any other option?

Summary:
MoBo : ASUS M2NPV-VM (PCI-e probably still ver.1.0)
Memory : Corsair TwinX 2x512Mb 800MHz (intent to add more 2x1Gb)
Processor : AMD Athlon 64 X2 3800+ AM2
current VGA : EAX1650Pro
PSU : Acbel 400w
HDD : 1x Regular SATA; 2xGreen SATA
Optical drive : 2x DVD-RW
need PhysX feature
no need SLI feature
intent to use to play games smootly at 1360x768 resolution or better

thanks for the help/advicess.

 

[eszaqsc]

mmm, well then ok, thanks for the advices

 

[eszaqsc]

Best answer selected by eszaqsc.