Photoshop - advice choosing my new HP

I am purchasing a new computer and software. I plan to get the HP Pavilion Elite 180t desktop. I've been using the old Photoshop CS for a few years, but I will be upgrading to Photoshop CS4. I will be using it to do layering for posters and for enhancing digital photos. I do not do gaming. I've read about problems some users have with speed and the graphics card. The Adobe site shows that they have tested two of the following graphics cards. What else should I know before I choose one of the following upgrades, if any? Thanks for any advice you can give.

1GB ATI Radeon HD 4650 [DVI, HDMI, VGA]
Performance-level graphics. Value price

1GB NVIDIA GeForce GT 220 [DVI, HDMI, VGA]
For enhanced multimedia experience

1GB ATI Radeon HD 4850 [2 DVI, HDMI and VGA adapters]
ATI`s TeraScale graphics engine delivers an immersive, cinematic gaming experience

1.8GB NVIDIA Geforce GTX 260 [2 DVI, HDMI and VGA adapters]
Gaming and media enthusiast graphics performance 1GB ATI Radeon HD 4650

I can't provide information on comparing those cards for Photoshop CS4. CS4 can use the graphics card to accelerate some functions:

GPU accelerated features in Photoshop CS4 and Bridge CS4

It looks like all of the cards would support those features. The Radeon 4850 and nVidia GTX 260 are both relatively high-end cards for gaming, but whether their additional power would be at all helpful for Photoshop, I don't know.

It may be more important to getWin7 X64 with lots of RAM, as the 64 bit version of PS CS4 can use it. I'd suggest the 12, 18, or 24 GB configurations, as they'd support the triple channel memory feature (maximum possible bandwidth). The 64 bit version can't use 32 bit plugins, though.

My suggestion would be if you can afford it always buy the best. As posted above I think the more Ram the better no matter which card you choose. Fabe

4650, and 8GB DDR3 1333MHz minimum. As has been noted 32-bit plugins will not work on 7 x86-64.