Graphic card upgrade for old Mac G5 a good idea?

Hello,

I am operating a 1.6 GHz PowerPC G5 with 2 GB DDR SDRAM.

The graphics card is an nVIDIA GeForce FX 5200 with 64Mb VRAM.

I have two displays, a 1680x1050 flat screen and a 1600x1200 CRT monitor.

I run Adobe Creative Suite 3 a lot. I have already discovered that the graphics card does not like dual monitors when using Adobe Bridge.

My two graphics card upgrade options are:

ATI Radeon 9200 128MB DVI/ VGA PCI card
ATI Radeon 9600 Pro 256MB DVI/ DVI AGP card

Will I see any performance increase when using two monitors OS X 10.4 and Indesign, Illustrator, Photoshop and Bridge in CS3?

(apologies if this topic has arisen before… I struggled to find it on a search).

regards,

Pete